Properly remove GhostViews when Activity Transition canceled.

Bug 25744941

When the returning Activity finished without transferring the
shared element, the shared elements in the underlying Activity
were left as GhostViews. This CL transfers the shared elements
back when the shared element transition is canceled.

Change-Id: I9062f1d439bb5364ac939788c67b20a739c0627b
1 file changed