[base] Migrate deprecated GrBackendSemaphore methods

See https://skia-review.googlesource.com/c/skia/+/781236 and https://skia-review.googlesource.com/c/skia/+/821978

Change-Id: I7f6494fff5c0341c895fd6145ca84583fea180fe
Bug: b/293490566
1 file changed