Merge branch '1386-app-lock-after-signout' into 'master'

Fix app lock after sign-out bug

Closes #1386

See merge request briar/briar!930

briar-android/src/main/java/org/briarproject/briar/android/account/LockManagerImpl.java

@@ -101,6 +101,8 @@ public class LockManagerImpl implements LockManager, Service, EventListener {
 
 	@Override
 	public void stopService() {
+		timeoutMinutes = timeoutNever;
+		if (alarmSet) alarmManager.cancel(lockIntent);
 	}
 
 	@UiThread