Fix lint and incorrect lifecycle owner

mobile/src/main/java/be/mygod/vpnhotspot/EBegFragment.kt

@@ -31,14 +31,14 @@ class EBegFragment : AppCompatDialogFragment() {
             }.setListener(this).build().also { it.startConnection(this) }
         }
 
-        override fun onBillingSetupFinished(billingResult: BillingResult?) {
-            if (billingResult?.responseCode == BillingClient.BillingResponseCode.OK) {
+        override fun onBillingSetupFinished(billingResult: BillingResult) {
+            if (billingResult.responseCode == BillingClient.BillingResponseCode.OK) {
                 billingClient.queryPurchases(BillingClient.SkuType.INAPP).apply {
                     if (responseCode == BillingClient.BillingResponseCode.OK) {
                         onPurchasesUpdated(this.billingResult, purchasesList)
                     }
                 }
-            } else Timber.e("onBillingSetupFinished: ${billingResult?.responseCode}")
+            } else Timber.e("onBillingSetupFinished: ${billingResult.responseCode}")
         }
 
         override fun onBillingServiceDisconnected() {
@@ -46,11 +46,11 @@ class EBegFragment : AppCompatDialogFragment() {
             billingClient.startConnection(this)
         }
 
-        override fun onPurchasesUpdated(billingResult: BillingResult?, purchases: MutableList<Purchase>?) {
-            if (billingResult?.responseCode == BillingClient.BillingResponseCode.OK && purchases != null) {
+        override fun onPurchasesUpdated(billingResult: BillingResult, purchases: MutableList<Purchase>?) {
+            if (billingResult.responseCode == BillingClient.BillingResponseCode.OK && purchases != null) {
                 // directly consume in-app purchase, so that people can donate multiple times
                 purchases.filter { it.purchaseState == Purchase.PurchaseState.PURCHASED }.map(this::consumePurchase)
-            } else Timber.e("onPurchasesUpdated: ${billingResult?.responseCode}")
+            } else Timber.e("onPurchasesUpdated: ${billingResult.responseCode}")
         }
 
         private fun consumePurchase(purchase: Purchase) = GlobalScope.launch(Dispatchers.Main.immediate) {

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -241,6 +241,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         if (!safeMode && key == KEY_OPERATING_CHANNEL) setOperatingChannel()
     }
 
+    @SuppressLint("NewApi") // networkId is available since Android 4.2
     private fun onPersistentGroupsChanged() {
         val channel = channel ?: return
         val device = binder.thisDevice ?: return

mobile/src/main/java/be/mygod/vpnhotspot/client/ClientsFragment.kt

@@ -109,10 +109,11 @@ class ClientsFragment : Fragment() {
                 "▲ ${Formatter.formatFileSize(app, send)}/s\t\t▼ ${Formatter.formatFileSize(app, receive)}/s"
     }
 
-    private inner class ClientViewHolder(val binding: ListitemClientBinding) : RecyclerView.ViewHolder(binding.root),
-            View.OnClickListener, PopupMenu.OnMenuItemClickListener {
+    private inner class ClientViewHolder(parent: ViewGroup, val binding: ListitemClientBinding =
+            ListitemClientBinding.inflate(LayoutInflater.from(parent.context), parent, false)) :
+            RecyclerView.ViewHolder(binding.root), View.OnClickListener, PopupMenu.OnMenuItemClickListener {
         init {
-            binding.lifecycleOwner = binding.root.findViewTreeLifecycleOwner()
+            binding.lifecycleOwner = parent.findViewTreeLifecycleOwner()!!
             binding.root.setOnClickListener(this)
             binding.description.movementMethod = LinkMovementMethod.getInstance()
         }
@@ -178,9 +179,7 @@ class ClientsFragment : Fragment() {
             binding.swipeRefresher.isRefreshing = false
         }
 
-        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
-                ClientViewHolder(ListitemClientBinding.inflate(LayoutInflater.from(parent.context), parent, false))
-
+        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = ClientViewHolder(parent)
         override fun onBindViewHolder(holder: ClientViewHolder, position: Int) {
             val client = getItem(position)
             holder.binding.client = client

mobile/src/main/java/be/mygod/vpnhotspot/net/TetherType.kt

@@ -59,8 +59,8 @@ enum class TetherType(@DrawableRes val icon: Int) {
         }
 
         @RequiresApi(30)
-        override fun onTetherableInterfaceRegexpsChanged() {
-            Timber.i("onTetherableInterfaceRegexpsChanged")
+        override fun onTetherableInterfaceRegexpsChanged(args: Array<out Any?>?) {
+            Timber.i("onTetherableInterfaceRegexpsChanged: ${args?.contentToString()}")
             TetheringManager.unregisterTetheringEventCallback(this)
             requiresUpdate = true
             listener()

mobile/src/main/java/be/mygod/vpnhotspot/net/TetheringManager.kt

@@ -333,7 +333,7 @@ object TetheringManager {
          * *@param reg The new regular expressions.
          * @hide
          */
-        fun onTetherableInterfaceRegexpsChanged() {}
+        fun onTetherableInterfaceRegexpsChanged(args: Array<out Any?>?) {}
 
         /**
          * Called when there was a change in the list of tetherable interfaces. Tetherable
@@ -437,7 +437,7 @@ object TetheringManager {
                                 callback?.onUpstreamChanged(args!![0] as Network?)
                             }
                             "onTetherableInterfaceRegexpsChanged" -> {
-                                if (regexpsSent) callback?.onTetherableInterfaceRegexpsChanged()
+                                if (regexpsSent) callback?.onTetherableInterfaceRegexpsChanged(args)
                                 regexpsSent = true
                             }
                             "onTetherableInterfacesChanged" -> {

mobile/src/main/java/be/mygod/vpnhotspot/net/wifi/SoftApConfigurationCompat.kt

@@ -1,5 +1,6 @@
 package be.mygod.vpnhotspot.net.wifi
 
+import android.annotation.SuppressLint
 import android.annotation.TargetApi
 import android.net.MacAddress
 import android.net.wifi.SoftApConfiguration
@@ -237,6 +238,7 @@ data class SoftApConfigurationCompat(
      * https://android.googlesource.com/platform/packages/apps/Settings/+/android-5.0.0_r1/src/com/android/settings/wifi/WifiApDialog.java#88
      * https://android.googlesource.com/platform/packages/apps/Settings/+/b1af85d/src/com/android/settings/wifi/tether/WifiTetherSettings.java#162
      */
+    @SuppressLint("NewApi") // https://android.googlesource.com/platform/frameworks/base/+/android-5.0.0_r1/wifi/java/android/net/wifi/WifiConfiguration.java#1385
     @Deprecated("Class deprecated in framework")
     @Suppress("DEPRECATION")
     fun toWifiConfiguration(): android.net.wifi.WifiConfiguration {