GuidedStep: support popping multiple entries transition

When finishGuidedStepFragments() is called, apply the
UI_STYLE_ENTRANCE on current fragment so it will run the
slide two sides returnTransition instead of slide one side
returnTransition.

Included a workaround of b/25375640

Change-Id: Ia8b15802a8e7a0c6f0466d1d5e6c8760c67483d0
3 files changed