Refactor recursive transform block size decoding
Refactor recursive transform block size decoding

Unify the transform block size to block size mapping.

Change-Id: Ic7359d016cd5965983c4a5476624c09f3123f91c

smarter/aom,GrokImageCompression/aom,luctrudeau/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom,smarter/aom,mbebenita/aom,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,smarter/aom,mbebenita/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,luctrudeau/aom,luctrudeau/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom