imageoverlay: Allow costume images with 1, 3 or 4 channels
imageoverlay: Allow costume images with 1, 3 or 4 channels

Change-Id: I33d8d58449d860999d505fd1642187c96c035c75

shelsonjava/kms-filters,shelsonjava/kms-filters,TribeMedia/kms-filters,Kurento/kms-filters,Kurento/kms-filters,shelsonjava/kms-filters,TribeMedia/kms-filters,TribeMedia/kms-filters,Kurento/kms-filters