Add Quick Settings tile (#660)

* Add Quick Settings tile

- Add multi-client support to AmneziaVpnService
- Make AmneziaActivity permanently connected to AmneziaVpnService while it is running
- Refactor processing of connection state changes on qt side
- Add VpnState DataStore
- Add check if AmneziaVpnService is running

* Add tile reset when the server is removed from the application

client/android/protocolApi/src/main/kotlin/ProtocolState.kt

@@ -2,9 +2,9 @@ package org.amnezia.vpn.protocol
 
 // keep synchronized with client/platforms/android/android_controller.h ConnectionState
 enum class ProtocolState {
+    DISCONNECTED,
     CONNECTED,
     CONNECTING,
-    DISCONNECTED,
     DISCONNECTING,
     RECONNECTING,
     UNKNOWN

client/android/protocolApi/src/main/kotlin/Status.kt

@@ -28,6 +28,10 @@ fun Bundle.putStatus(status: Status) {
     putInt(STATE_KEY, status.state.ordinal)
 }
 
+fun Bundle.putStatus(state: ProtocolState) {
+    putInt(STATE_KEY, state.ordinal)
+}
+
 fun Bundle.getStatus(): Status =
     Status.build {
         setState(ProtocolState.entries[getInt(STATE_KEY)])