Fix alignment and copy size for legacy QCOM OMX (from https://github.com/grigorig/)

Change-Id: I5fa6e57fe213a534a0def6d8c21c2f1475982e65
Prefer 16bpp formats for opaque bitmaps

Configure BitmapFactory to prefer RGB565, which will make it
use that format for all opaque assets loaded by it with standard
settings. Toggle dithering flag in strategic places and reenable
16bpp drawing cache, to speed up software UI rendering.

(Original author: Grigori Goronzy <greg@blackbox>)

Change-Id: I292f77a4481e86964255d7b59c9407f5e99a8e08
Prefer 16bpp surface formats

Adds a property to use RGB565 surface formats for the opaque
surface default, enabled by default.

(Original author: Grigori Goronzy <greg@blackbox>)

Change-Id: Ia5aa00b9fcb197d25f7107a569103389a0337eb3
Use RGB565 surface for wallpaper

The framebuffer only uses 16bpp on most legacy devices anyway, so this
does not result in worse quality. It saves a lot of GPU fillrate and
memory, though.

(Original author: Grigori Goronzy <greg@blackbox>)

Change-Id: I0133dec0ee0e122248027b422ba13b03f55e57a9