Rename sg tests and samples targets to fix Visual Studio name conflict

GN was emitting projects for the SG versions of tests and samples, which
conflicted with the top-level versions of those. This made the normal GN
VS IDE files confusing, and the merged ones totally broken.

Change-Id: Ifd048258d4358ed2852d5263b16278c5b8ebd9c4
Reviewed-on: https://skia-review.googlesource.com/131391
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
2 files changed