Rename 'DefaultSettings' golden outputs to 'StandaloneSettings'.

I realized that "DefaultSettings" as a name suffix was unclear, because
"Default" is a different settings mode from skslc running with
--nosettings.
In --nosettings mode, skslc uses "standalone" settings.

Change-Id: I1f5d80df0a21cec55948c4ad146169bcb34f4999
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/318210
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
46 files changed