AnimEncoder API: Fix for kmax=1 and default kmin case.
AnimEncoder API: Fix for kmax=1 and default kmin case.

Some frames that were previously selected as key-frames were incorrectly
being reset to sub-frames.

Change-Id: Iee342dbb9a9aec144b8185c3b54ca56aa7038bfb

PKRoma/libwebp,Suvarna1488/webm.libwebp,jiehu5114/libwebp,abwiz0086/webm.libwebp,ttyangf/libwebp,rxl194/libwebp,kim42083/webm.libwebp,ericmckean/webm.libwebp,iniwf/webm.libwebp,webmproject/libwebp,matanbs/webm.libwebp,Maria1099/webm.libwebp,yohunl/libwebp,yohunl/libwebp,kim42083/webm.libwebp,kalli123/webm.libwebp,webmproject/libwebp,jacklicn/libwebp,zofuthan/libwebp,zofuthan/libwebp,Suvarna1488/webm.libwebp,jacklicn/libwebp,ttyangf/libwebp,redengineer/libwebp,PKRoma/libwebp,kleopatra999/webm.libwebp,gshORTON/webm.libwebp,reimaginemedia/webm.libwebp,yohunl/libwebp,abwiz0086/webm.libwebp,redengineer/libwebp,Acidburn0zzz/webm.libwebp,Aexyn/libwebp,PKRoma/libwebp,ya7lelkom/libwebp,kim42083/webm.libwebp,webmproject/libwebp,zofuthan/libwebp,reimaginemedia/webm.libwebp,altogother/webm.libwebp,Aexyn/libwebp,ericmckean/webm.libwebp,kalli123/webm.libwebp,abwiz0086/webm.libwebp,jacklicn/libwebp,Suvarna1488/webm.libwebp,kleopatra999/webm.libwebp,altogother/webm.libwebp,kleopatra999/webm.libwebp,jacklicn/libwebp,matanbs/webm.libwebp,ericmckean/webm.libwebp,PKRoma/libwebp,gshORTON/webm.libwebp,kleopatra999/webm.libwebp,imazen/libwebp,kalli123/webm.libwebp,kim42083/webm.libwebp,kalli123/webm.libwebp,redengineer/libwebp,iniwf/webm.libwebp,ttyangf/libwebp,kleopatra999/webm.libwebp,kalli123/webm.libwebp,imazen/libwebp,jiehu5114/libwebp,rxl194/libwebp,iniwf/webm.libwebp,Maria1099/webm.libwebp,ya7lelkom/libwebp,yohunl/libwebp,Aexyn/libwebp,gshORTON/webm.libwebp,PKRoma/libwebp,Acidburn0zzz/webm.libwebp,ttyangf/libwebp,Maria1099/webm.libwebp,reimaginemedia/webm.libwebp,abwiz0086/webm.libwebp,ericmckean/webm.libwebp,ya7lelkom/libwebp,gshORTON/webm.libwebp,Suvarna1488/webm.libwebp,yohunl/libwebp,iniwf/webm.libwebp,ttyangf/libwebp,Aexyn/libwebp,Acidburn0zzz/webm.libwebp,rxl194/libwebp,rxl194/libwebp,Acidburn0zzz/webm.libwebp,altogother/webm.libwebp,imazen/libwebp,reimaginemedia/webm.libwebp,altogother/webm.libwebp,imazen/libwebp,webmproject/libwebp,zofuthan/libwebp,jiehu5114/libwebp,rxl194/libwebp,Acidburn0zzz/webm.libwebp,zofuthan/libwebp,Aexyn/libwebp,ericmckean/webm.libwebp,abwiz0086/webm.libwebp,Maria1099/webm.libwebp,jiehu5114/libwebp,gshORTON/webm.libwebp,webmproject/libwebp,PKRoma/libwebp,kim42083/webm.libwebp,matanbs/webm.libwebp,ya7lelkom/libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,iniwf/webm.libwebp,redengineer/libwebp,redengineer/libwebp,jiehu5114/libwebp,jacklicn/libwebp,imazen/libwebp,ya7lelkom/libwebp,Maria1099/webm.libwebp,matanbs/webm.libwebp,Suvarna1488/webm.libwebp,reimaginemedia/webm.libwebp