Support monitoring tethered interface

This would be useful to be used in together with Instant Tethering + Turn off hotspot automatically.

Refine #26, #53.

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

@@ -4,6 +4,7 @@ import android.content.Intent
 import android.view.View
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.RecyclerView
+import be.mygod.vpnhotspot.R
 import be.mygod.vpnhotspot.TetheringService
 import be.mygod.vpnhotspot.databinding.ListitemInterfaceBinding
 import be.mygod.vpnhotspot.net.TetherType
@@ -30,12 +31,14 @@ class InterfaceManager(private val parent: TetheringFragment, val iface: String)
     }
     private inner class Data : be.mygod.vpnhotspot.manage.Data() {
         override val icon get() = TetherType.ofInterface(iface).icon
-        override val title get() = iface
+        override val title get() = if (parent.binder?.monitored(iface) == true) {
+            parent.getString(R.string.tethering_state_monitored, iface)
+        } else iface
         override val text get() = addresses
         override val active get() = parent.binder?.isActive(iface) == true
     }
 
-    private val addresses = parent.ifaceLookup[iface]?.formatAddresses() ?: ""
+    private val addresses = parent.ifaceLookup[iface] ?.formatAddresses(parent.binder?.isInactive(iface) == true) ?: ""
     override val type get() = VIEW_TYPE_INTERFACE
     private val data = Data()