Add dual_filter into the experimental flag list
Add dual_filter into the experimental flag list

Change-Id: I3f240fb46716b70e7c0ddd40660f55e1285875cd

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