Add parameter search to global motion computation
Add parameter search to global motion computation

Change-Id: I66ea5a819ab54ecb5327eee20f798d7d7f0833d3

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