Add ImageView-specific shared element activity transition code.

Bug 14497858

Probably more than 50% of shared elements will be ImageViews and
sharing the scale type and matrix between the two Activities will
simplify shared element transitions.

Also fixed MoveImage, which had a bug when the scale type was FIX_XY.

Change-Id: Ic5548b4d1420ced12507c18edf76c9e50e27a929