Drop exception stubs because GeckoView now drags in the conflicting real ones

app/src/main/java/com/google/android/gms/common/GooglePlayServicesNotAvailableException.java

@@ -1,12 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-package com.google.android.gms.common;
-
-public class GooglePlayServicesNotAvailableException extends Exception {
-
-    public GooglePlayServicesNotAvailableException(int arg1) {
-    }
-
-}

app/src/main/java/com/google/android/gms/common/GooglePlayServicesRepairableException.java

@@ -1,10 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-package com.google.android.gms.common;
-
-public class GooglePlayServicesRepairableException extends Exception {
-    public GooglePlayServicesRepairableException(int arg1, String arg2, Object arg3) {
-    }
-}