Merge branches 'serialize_sealed_classes' and 'serialize_sealed_classes' of https://github.com/iruizmar/firebase-kotlin-sdk into serialize_sealed_classes

Author: iruizmar

gradle.properties

@@ -25,7 +25,7 @@ firebase-app.skipIosTests=false
 firebase-auth.skipIosTests=true
 firebase-common.skipIosTests=false
 firebase-config.skipIosTests=false
-firebase-database.skipIosTests=false
+firebase-database.skipIosTests=true
 firebase-firestore.skipIosTests=false
 firebase-functions.skipIosTests=false
 firebase-installations.skipIosTests=false