Remove references to SkImageDecoder (part 2)

As of this CL, SkImageDecoder is no longer used in Android and
will be deleted by Skia.

(cherry picked from commit 097a6ea4b65046df3e3cbf93d1acfc4e6833e02f)

Change-Id: Ic754ab0dde7ad1b65ccf3b2bc23fcbc5ef44ed08
3 files changed