Fix ActiveMap failure in ref-mv scheme
Fix ActiveMap failure in ref-mv scheme

Reset the ref_mv_idx and predicted motion vector when the coding
block belongs to skip segment.

Change-Id: I416545f1648fef5b537afa25de469f54c49a86ed

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