Bug: 28914094
In split screen the dialog content is too tall to fit in viewport. Wrap
content in a scrollview so user can scroll vertically for different
options, and have a visual indication that content is scrollable.
Change-Id: Ia304dca6747cec6f31e86ccf89003ef6890e0640
This makes the lifecycle simpler to fix a crash after rotation.
Also do some adjusting of alignment while here.
Bug: 21444336
Bug: 21205689
Change-Id: I67eccf4833f53b5e5088ae5e6038d041e8653565
