Fix the bug in ApplyPalette.
Fix the bug in ApplyPalette.

The auto-infer logic of detecting the 'Alpha' use case
(via check '(palette[i] & 0x00ff00ffu) != 0' is failing
for this corner case image with all black pixels (rgb = 0)
and different Alpha values.

-> switch generic use-LUT detection

Change-Id: I982a8b28c8bcc43e3dc68ac358f978a4bcc14c36

Acidburn0zzz/webm.libwebp,Suvarna1488/webm.libwebp,PKRoma/libwebp,imazen/libwebp,yohunl/libwebp,abwiz0086/webm.libwebp,PKRoma/libwebp,kleopatra999/webm.libwebp,comoyo/gonzo-libwebp,rxl194/libwebp,Aexyn/libwebp,kleopatra999/webm.libwebp,altogother/webm.libwebp,yohunl/libwebp,reimaginemedia/webm.libwebp,imazen/libwebp,Tekserve/libwebp,webmproject/libwebp,abwiz0086/webm.libwebp,reimaginemedia/webm.libwebp,iniwf/webm.libwebp,zofuthan/libwebp,reimaginemedia/webm.libwebp,kim42083/webm.libwebp,jacklicn/libwebp,zofuthan/libwebp,ericmckean/webm.libwebp,jacklicn/libwebp,Suvarna1488/webm.libwebp,jiehu5114/libwebp,ya7lelkom/libwebp,keane83/BLE_IM,kleopatra999/webm.libwebp,comoyo/gonzo-libwebp,keane83/BLE_IM,redengineer/libwebp,keane83/BLE_IM,iniwf/webm.libwebp,ttyangf/libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,kleopatra999/webm.libwebp,redengineer/libwebp,zofuthan/libwebp,abwiz0086/webm.libwebp,yohunl/libwebp,gshORTON/webm.libwebp,Aexyn/libwebp,abwiz0086/webm.libwebp,zofuthan/libwebp,webmproject/libwebp,Suvarna1488/webm.libwebp,zofuthan/libwebp,gshORTON/webm.libwebp,ericmckean/webm.libwebp,redengineer/libwebp,Maria1099/webm.libwebp,appunite/libwebp,Maria1099/webm.libwebp,webmproject/libwebp,ttyangf/libwebp,matanbs/webm.libwebp,Maria1099/webm.libwebp,kim42083/webm.libwebp,PKRoma/libwebp,Maria1099/webm.libwebp,comoyo/gonzo-libwebp,redengineer/libwebp,comoyo/gonzo-libwebp,webmproject/libwebp,ya7lelkom/libwebp,ya7lelkom/libwebp,Acidburn0zzz/webm.libwebp,Tekserve/libwebp,jacklicn/libwebp,Tekserve/libwebp,ttyangf/libwebp,jiehu5114/libwebp,Acidburn0zzz/webm.libwebp,kim42083/webm.libwebp,altogother/webm.libwebp,webmproject/libwebp,altogother/webm.libwebp,rxl194/libwebp,iniwf/webm.libwebp,Suvarna1488/webm.libwebp,yohunl/libwebp,Aexyn/libwebp,appunite/libwebp,iniwf/webm.libwebp,reimaginemedia/webm.libwebp,appunite/libwebp,jiehu5114/libwebp,altogother/webm.libwebp,matanbs/webm.libwebp,kalli123/webm.libwebp,kim42083/webm.libwebp,reimaginemedia/webm.libwebp,appunite/libwebp,imazen/libwebp,Aexyn/libwebp,ttyangf/libwebp,ericmckean/webm.libwebp,gshORTON/webm.libwebp,gshORTON/webm.libwebp,rxl194/libwebp,kalli123/webm.libwebp,jiehu5114/libwebp,gshORTON/webm.libwebp,comoyo/gonzo-libwebp,iniwf/webm.libwebp,matanbs/webm.libwebp,ya7lelkom/libwebp,imazen/libwebp,jacklicn/libwebp,ericmckean/webm.libwebp,redengineer/libwebp,PKRoma/libwebp,Tekserve/libwebp,jacklicn/libwebp,rxl194/libwebp,comoyo/gonzo-libwebp,kalli123/webm.libwebp,PKRoma/libwebp,appunite/libwebp,jiehu5114/libwebp,kim42083/webm.libwebp,Suvarna1488/webm.libwebp,abwiz0086/webm.libwebp,yohunl/libwebp,kalli123/webm.libwebp,keane83/BLE_IM,Acidburn0zzz/webm.libwebp,kleopatra999/webm.libwebp,ttyangf/libwebp,kalli123/webm.libwebp,PKRoma/libwebp,rxl194/libwebp,imazen/libwebp,keane83/BLE_IM,Acidburn0zzz/webm.libwebp,Aexyn/libwebp,comoyo/gonzo-libwebp,ya7lelkom/libwebp,matanbs/webm.libwebp,appunite/libwebp,ericmckean/webm.libwebp,Maria1099/webm.libwebp