Rename ES2 error tests starting with 'B' to .rts.

A few tests received minor tweaks to make them Runtime Effect-friendly.

Bug: skia:13042
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Change-Id: I02a469b241735fa15d86e292eaa4ef4aa9cc8af6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/524097
Reviewed-by: Derek Sollenberger <djsollen@google.com>
14 files changed