Remove assert that BGRA and RGBA are not opaque

Bug: skia:7353
Bug: skia:8235

This should fix the Wuffs bot. A recent change set SkWuffsCodec's
SkEncodedInfo::Color to BGRA or RGBA even if they are opaque, which
resulted in this assert firing. As has been brought up previously,
SkEncodedInfo::Color is overspecified. The only code that cares
about the type is SkSwizzler, which will treat the alpha as
potentially non-opaque (whereas BGRX_Color (there is no RGBX_Color)
ignores the alpha channel, which is important for some BMPs).

TBR=reed@google.com

Change-Id: I3396b53aef114e09513579f829c5b5345acba4f0
Reviewed-on: https://skia-review.googlesource.com/c/193028
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
1 file changed