GuidedStepFragment: fix the unfocus alpha being overriden.

A regression of fixing b/20759626: if onAnimateItemFocused()
changes item alpha,  it will be overriden by animator created by
onAnimateItemPressed(false).

Introduce onAnimateItemPressedCancelled() which sets alpha without animation.
Let onAnimateItemFocused() be executed after onAnimateItemPressedCancelled().

Bug 20759626

Change-Id: I61d100d93c47afa1ad9dc6c070dc9477eb092dc9
3 files changed