Work-around paletted image decoding bug in SDK_JELLYBEAN

Because there is a bug decoding paletted images in SDK_JELLYBEAN,
we need to avoid encoding paletted images for apps that support
SDK_JELLYBEAN and earlier.

BUG=27643907

Change-Id: Ib7d51ed87435cd36507915d62b0057c06f18b2b6