Make incoming call screen style configurable. (2/3)

Change-Id: I46db78c9b48fae52530b96789ec2721d51b7185a
Avoid layout changes on call disconnection.

This avoids showing the call buttons when an incoming call is
disconnected remotely while still ringing, which in turn avoids an ugly
transition when using the full screen caller photo.

Change-Id: If69bce271303ea43dca64925aba895dd3b5b5611
Automatic translation import

Change-Id: Idacecf17c39964c5f25ed1f60ba5e57af18ed313
Automatic translation import

Change-Id: I5ccecbf50a807c1bc6e98fddc4e26bc348649eaa
Fix call buttons being incorrectly hidden.

They were hidden incorrectly when having full-screen caller photo
enabled and an outgoing call is terminated without being answered.

Change-Id: I817a1f8d37c83aabb5470ee1ed6329b79302d338