Enable firebase-database JS tests

Author: shepeliev

gradle.properties

@@ -40,7 +40,7 @@ firebase-app.skipJsTests=false
 firebase-auth.skipJsTests=false
 firebase-common.skipJsTests=false
 firebase-config.skipJsTests=false
-firebase-database.skipJsTests=true
+firebase-database.skipJsTests=false
 firebase-firestore.skipJsTests=false
 firebase-functions.skipJsTests=false
 firebase-installations.skipJsTests=false