Adding the @firebase/database in the dependencies

Author: Samruddhi90

packages/remote-config/package.json

@@ -44,7 +44,8 @@
     "@firebase/logger": "0.4.4",
     "@firebase/util": "1.12.0",
     "@firebase/component": "0.6.17",
-    "tslib": "^2.1.0"
+    "tslib": "^2.1.0",
+    "@firebase/database": "1.0.19"
   },
   "license": "Apache-2.0",
   "devDependencies": {