Firebase Database Rules issue in android sdk

I'm using Firebase android sdk for database and authentication. Initially android app works well(set/retrieve data from database and authentication), but when i changed the database rules to the following, app stopped retrieving data or setting data in the database.

".read": "auth != null",
".write": "auth != null"

My android app always checks for auth and then only it starts to retrieve data otherwise my app popup login screen. Someone please suggest a way for solving this issue.