[js][all] added nativeSDKMissing check for all modules - part of making all module native sdk's optional.

lib/modules/database/index.js

@@ -8,7 +8,7 @@ import { Base } from './../base';
 import Snapshot from './snapshot';
 import Reference from './reference';
 import TransactionHandler from './transaction';
-import { promisify } from './../../utils';
+import { promisify, nativeSDKMissing } from './../../utils';
 
 const FirebaseDatabase = NativeModules.RNFirebaseDatabase;
 const FirebaseDatabaseEvt = new NativeEventEmitter(FirebaseDatabase);
@@ -19,6 +19,10 @@ const FirebaseDatabaseEvt = new NativeEventEmitter(FirebaseDatabase);
 export default class Database extends Base {
   constructor(firebase: Object, options: Object = {}) {
     super(firebase, options);
+    if (FirebaseDatabase.nativeSDKMissing) {
+      return nativeSDKMissing('database');
+    }
+
     this.references = {};
     this.serverTimeOffset = 0;
     this.persistenceEnabled = false;
@@ -83,12 +87,10 @@ export default class Database extends Base {
    * @param origCB
    * @returns {*}
    */
-  off(
-    refId: number,
-    // $FlowFixMe
-    listeners: Array<DatabaseListener>,
-    remainingListenersCount: number
-  ) {
+  off(refId: number,
+      // $FlowFixMe
+      listeners: Array<DatabaseListener>,
+      remainingListenersCount: number) {
     this.log.debug('off() : ', refId, listeners);
 
     // Delete the reference if there are no more listeners