This commit does few things:
1. Gets doCompressedTexImage2D out of the context and TextureUtils
2. Gets palette textures out of TextureUtils and into PaletteTexture
3. Makes TextureUtils generic for all compressed textures
4. Moves the glGet's dealing with compressed textures from GLEScontext to the impl.
Change-Id: Ibbde6968810a66a4f3488f3887ee3f015fc32c11