do not use Dialer UI for incoming calls if audio permission is not granted

We cannot request new permissions when Dialer UI is shown. For incoming
calls, if the Dialer UI is displayed over keyguard, then the user may
not even be able to see the permission notifications that we use for
outgoing calls.

If we just do not use the Dialer UI when the permission is not granted,
it is at most a minor annoyance for the first time. After the user has
accepted an incoming call even just once, the permission will be
granted, and the Dialer integration will start to work just fine.

src/cheogram/java/com/cheogram/android/ConnectionService.java

@@ -68,17 +68,8 @@ public class ConnectionService extends android.telecom.ConnectionService {
 		}
 	};
 
-	private PermissionManager mPermissionManager;
-
 	@Override
 	public void onCreate() {
-		mPermissionManager = PermissionManager.getInstance(this);
-		mPermissionManager.setNotificationSettings(
-				new NotificationSettings.Builder()
-						.withMessage(R.string.microphone_permission_for_call)
-						.withSmallIcon(R.drawable.ic_notification).build()
-		);
-
 		// From XmppActivity.connectToBackend
 		Intent intent = new Intent(this, XmppConnectionService.class);
 		intent.setAction("ui");
@@ -124,9 +115,16 @@ public class ConnectionService extends android.telecom.ConnectionService {
 		Jid with = Jid.ofLocalAndDomain(tel, gateway[1]);
 		CheogramConnection connection = new CheogramConnection(account, with, postDial);
 
+		PermissionManager permissionManager = PermissionManager.getInstance(this);
+		permissionManager.setNotificationSettings(
+				new NotificationSettings.Builder()
+						.withMessage(R.string.microphone_permission_for_call)
+						.withSmallIcon(R.drawable.ic_notification).build()
+		);
+
 		Set<String> permissions = new HashSet<>();
 		permissions.add(Manifest.permission.RECORD_AUDIO);
-		mPermissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
+		permissionManager.checkPermissions(permissions, new PermissionManager.PermissionRequestListener() {
 			@Override
 			public void onPermissionGranted() {
 				connection.setSessionId(xmppConnectionService.getJingleConnectionManager().proposeJingleRtpSession(

src/main/java/eu/siacs/conversations/services/NotificationService.java

@@ -467,8 +467,8 @@ public class NotificationService {
         try {
             telecomManager.addNewIncomingCall(handle, callInfo);
         } catch (SecurityException e) {
-            // There *could* be race conditions where the account is not registered yet
-            // when an incoming call is already received
+            // If the account is not registered or enabled, it could result in a security exception
+            // Just fall back to the built-in UI in this case.
             Log.w(Config.LOGTAG, e);
             return false;
         }