FirebaseUI for Android v2.4.0

FirebaseUI for Android v2.4.0 contains a number of bug fixes and small feature improvements:

Auth:

• Add ability to pass phone number into auth flow (#887)
• Fixed IllegalArgumentException in PhoneVerificationActivity (#922)
• Fixed NullPointerException in CompletableProgressDialog (#921)
• Fixed IllegalStateException in CompletableProgressDialog (#914)
• Removes fabric API key from manifest (#904)
• Fix enter behavior on email signup (#869)

Database:

• Improved performance and better handling of null snapshots (#871)

Storage:

• No changes

This version has the following notable transitive dependencies:

Dependency	Version
Firebase / Play services	11.4.0
Support Library	26.0.1