Handle fallback Bluetooth starting

mobile/src/main/java/be/mygod/vpnhotspot/manage/BluetoothTethering.kt

@@ -110,12 +110,13 @@ class BluetoothTethering(context: Context, private val adapter: BluetoothAdapter
      */
     @SuppressLint("MissingPermission")
     @RequiresApi(24)
-    fun start(callback: TetheringManager.StartTetheringCallback) {
+    fun start(callback: TetheringManager.StartTetheringCallback, context: Context) {
         if (pendingCallback == null) try {
             if (adapter.state == BluetoothAdapter.STATE_OFF) {
                 registerBluetoothStateListener(BluetoothTethering)
                 pendingCallback = callback
-                adapter.enable()
+                @Suppress("DEPRECATION")
+                if (!adapter.enable()) context.startActivity(Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE))
             } else TetheringManager.startTethering(TetheringManager.TETHERING_BLUETOOTH, true, callback)
         } catch (e: SecurityException) {
             SmartSnackbar.make(e.readableMessage).shortToast().show()

mobile/src/main/java/be/mygod/vpnhotspot/manage/TetherManager.kt

@@ -334,7 +334,7 @@ sealed class TetherManager(protected val parent: TetheringFragment) : Manager(),
                 if (tethering.active == null) tethering.activeFailureCause?.readableMessage else null,
                 baseError).joinToString("\n")
 
-        override fun start() = tethering.start(this)
+        override fun start() = tethering.start(this, parent.requireContext())
         override fun stop() {
             tethering.stop(this::onException)
             onTetheringStarted()    // force flush state

mobile/src/main/java/be/mygod/vpnhotspot/manage/TetheringTileService.kt

@@ -153,7 +153,7 @@ sealed class TetheringTileService : IpNeighbourMonitoringTileService(), Tetherin
         override val labelString get() = R.string.tethering_manage_bluetooth
         override val tetherType get() = TetherType.BLUETOOTH
 
-        override fun start() = tethering!!.start(this)
+        override fun start() = tethering!!.start(this, this)
         override fun stop() {
             tethering!!.stop(this::onException)
             onTetheringStarted()    // force flush state