Rotate thumbnail view based off device orientation

In landscape mode, recents thumbnails should be shown horizontally, so
this CL modifies the custom view so that it resizes to display a
horizontal snapshot.

Bug: 114136250
Bug: 131095241
Test: Rotate recents, see view width change appropriately
Change-Id: Ic3d8d039535c673567d19c372da211d177691a81