GuidedStepFragment: two columns actions

Duplicated action methods into another copy.

The weight of actions width is controlled through theme:
guidedActionContentWidthWeight, guidedActionContentWidthWeightTwoPanels.
When there is one column: actions take 40% of screen width.
When there are two columns: actions take 50% of screen width.

Two actions backgrounds are controlled through theme:
guidedActionsBackground, guidedButtonActionsBackground.

b/24979563

Change-Id: I96486921c39693771c243b18ef9897aa750c65cb
13 files changed