GuidedStepFragment: allow move focus to button action list

Add a GuidedActionAdapterGroup to maintain single ImeOpen flag and
control next focus after editing.  This would allow focus move
between different action lists.
Code refactoring moves editing logic from GuidedActionAdapter into
GuidedActionAdapterGroup.

Don't openIME in onKeyUp event, this causes timing issue that onKeyUp
can be fired on a different view of keyDown. Move openIME into onClick
event.

Remove references to Adapter objects and view objects after Fragment
onDestroyView(), fix potential View leaking.

Change-Id: If89a7bf67bd62ff02d3ac2a2c64a1164d3fa76bd
6 files changed