Disable questionable bmps on Mac platform decoder

These are already disabled on WIC, but they are supported by SkCodec.

Bug: skia:6984
Change-Id: Ib248749f357debcc173dfaa2bcd5adc8da52df22
Reviewed-on: https://skia-review.googlesource.com/36440
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
12 files changed