Change how Java Bitmaps are accessed in a few places

Stop assuming that a Java Bitmap has a SkBitmap* that
has some externally managed lifecycle, and instead switch
a bunch of users to accessing the bitmap by providing
their own SkBitmap* on which to set the (ref counted!)
SkPixelRef* instead

Attempt #2 to land this, original issue was in getSkBitmap
and should be fixed

Change-Id: I0fd9e193968b41e5597784140d56b4885906864a