Merge "Move some implicitly shared testing code for bp2build into testing.go."...

Merge "Move some implicitly shared testing code for bp2build into testing.go." am: e2f45d3e am: 68b8e17c am: 29005a5b am: 7a265641

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1712090

Change-Id: Ib03a3fa3fcbed67df51b08747d9f941c0a28221a