Fix closed interface

Signed-off-by: Mario Danic <mario@lovelyhq.com>

app/src/main/java/com/nextcloud/talk/interfaces/ClosedInterface.java

@@ -22,4 +22,5 @@ package com.nextcloud.talk.interfaces;
 
 public interface ClosedInterface {
     void providerInstallerInstallIfNeededAsync();
+    boolean isGooglePlayServicesAvailable();
 }