Remove dependencies on Android's forked decoder libraries

Disable SkImageDecoder's code which relies on Android's customized
libpng and libjpeg. Build standard versions of libpng and libjpeg-turbo
everywhere. The SkImageDecoder code has been replaced with SkCodec, which
can decode subsets using standard library APIs

BUG=skia:

Review URL: https://codereview.chromium.org/1406153015
13 files changed