In the build there are some defaults which actually apply to every
use of a built-in target type, but there are some (particularaly
warnings) which apply only to targets controlled by Skia. Currently
these unwanted defaults are magically known to exist and removed
wherever they are not wanted. Instead, create 'skia_' prefixed target
templates and apply these defaults to those instead.
Change-Id: I3a2afb53c7205a2e2748d1cfad46319f2e93d3b3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385516
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
