Pass color types when creating texture with initial data.

One describes the color type use case for the texture and the other
the color type of the texel data, a la writePixels().

Bug: skia:6718

Change-Id: I3ca2ab9f76aaeca4b2861a171b1aaacaa0709d1e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240679
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
19 files changed