fix invalid omittion of GCM registration

app/src/main/java/chat/rocket/android/model/internal/GcmPushRegistration.java

@@ -41,6 +41,15 @@ public class GcmPushRegistration extends RealmObject {
 
   public static GcmPushRegistration updateGcmPushEnabled(Realm realm, boolean gcmPushEnabled)
       throws JSONException {
+    GcmPushRegistration gcmPushRegistration = GcmPushRegistration.queryDefault(realm).findFirst();
+    if (gcmPushRegistration != null
+        && (gcmPushRegistration.getSyncState() == SyncState.NOT_SYNCED
+         || gcmPushRegistration.getSyncState() == SyncState.SYNCING)
+        && gcmPushEnabled == gcmPushRegistration.isGcmPushEnabled()) {
+      // omit duplicated request.
+      return gcmPushRegistration;
+    }
+
     return realm.createOrUpdateObjectFromJson(GcmPushRegistration.class, new JSONObject()
         .put(ID, DEFAULT_ID)
         .put(SYNC_STATE, SyncState.NOT_SYNCED)

app/src/main/java/chat/rocket/android/push/gcm/GcmInstanceIDListenerService.java

@@ -33,10 +33,7 @@ public class GcmInstanceIDListenerService extends InstanceIDListenerService {
         GcmPushSettingHelper::queryForGcmPushEnabled);
     final boolean gcmPushEnabled = GcmPushSettingHelper.isGcmPushEnabled(results);
 
-    GcmPushRegistration gcmPushRegistration = realmHelper.executeTransactionForRead(realm ->
-        GcmPushRegistration.queryDefault(realm).findFirst());
-
-    if (gcmPushRegistration == null || gcmPushEnabled != gcmPushRegistration.isGcmPushEnabled()) {
+    if (gcmPushEnabled) {
       realmHelper.executeTransaction(realm ->
           GcmPushRegistration.updateGcmPushEnabled(realm, gcmPushEnabled));
     }

app/src/main/java/chat/rocket/android/service/observer/PushSettingsObserver.java

@@ -27,10 +27,7 @@ public class PushSettingsObserver extends AbstractModelObserver<PublicSetting> {
   public void onUpdateResults(List<PublicSetting> results) {
     boolean gcmPushEnabled = GcmPushSettingHelper.isGcmPushEnabled(results);
 
-    GcmPushRegistration gcmPushRegistration = realmHelper.executeTransactionForRead(realm ->
-        GcmPushRegistration.queryDefault(realm).findFirst());
-
-    if (gcmPushRegistration == null || gcmPushEnabled != gcmPushRegistration.isGcmPushEnabled()) {
+    if (gcmPushEnabled) {
       realmHelper.executeTransaction(realm ->
           GcmPushRegistration.updateGcmPushEnabled(realm, gcmPushEnabled));
     }