[database] - Add database namespace + enableLogging function to follow web docs

Author: KkevinLi

src/app/index.ts

@@ -52,6 +52,14 @@ export function firestore(app?: any): firebaseFirestoreModule.Firestore {
 
 let functionsCache;
 
+export namespace database {
+  // This is just to follow the webs interface. On android and ios enable logging only accepts a boolean
+  // By default logging is set to Info. We will set to debug if true and none if false.
+  export function enableLogging(logger?: boolean | ((a: string) => any), persistent?: boolean): any {
+    firebase.enableLogging(logger, persistent);
+  }
+}
+
 export function functions(app?: any): firebaseFunctionsModule.Functions {
   if (app) {
     console.log("The 'app' param is ignored at the moment.");