5.0.0 has no breaking API changes from version
4.3.2 but updates some
critical dependencies to new major versions.
In order to use FirebaseUI, make sure your application does not declare any of the following dependencies at a lower version:
com.google.firebase:firebase-core:16.0.9 com.google.firebase:firebase-auth:17.0.0 com.google.firebase:firebase-firestore:19.0.0 com.google.firebase:firebase-database:17.0.0 com.google.firebase:firebase-storage:17.0.0
All of the underlying breaking changes were part of the May 7th Firebase SDK release. You can read more about this release here: https://firebase.google.com/support/release-notes/android#update_-_may_07_2019