Fix issues with photo selection on Prime.

1. Per Marco's request, we no longer expand the photo in landscape
   on phone.
2. Passing the full bitmap through the intent appears to be a no-no,
   which was exposed in the "black-screen" behavior when clicking on
   a default avatar photo on Prime.  To handle that, we now retrieve
   the photo from the default avatar resource if no URI is specified,
   and we retrieve the bitmap for real photos through the photo
   manager cache.  To ensure performance, I've added a method to the
   cache to force caching a given bitmap/byte[] for a photo URI.

Bug 5703659
Bug 5703700

Change-Id: I316f27c7ded575dd1bb00c0bb2e2c75917df1e19
5 files changed