Fix Palette errors when using region API

Instead of using getPixels() to retrieve the
region, we'll just manually do it from the whole
Bitmap. We get the whole bitmap anyway so technically
this is less work.

Also improved our RGB565 --> RGB888 upscale to use scaling
rather than shifting. This produces more reliable results.

BUG: 28349435
Change-Id: I19bd2d2be3794194fa08931024b545269d85724b
4 files changed