Revert of switch to isABitmap, deprecate SK_SUPPORT_LEGACY_SHADERBITMAPTYPE (patchset #3 id:40001 of https://codereview.chromium.org/1311963007/ )

Reason for revert:
Broke the Android canary:

  https://internal.skia.org/builders/crimson-cherry-474438/builds/124

Original issue's description:
> switch to isABitmap, deprecate SK_SUPPORT_LEGACY_SHADERBITMAPTYPE
>
> BUG=skia:
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/2d126b5c45e65a67a9945afa9294038a8eb3f2c8

TBR=reed@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1309943004
5 files changed