Merge "Add system staging dir stamp file for bazel sandwich" into main am:...

Merge "Add system staging dir stamp file for bazel sandwich" into main am: e88ddaec am: f0ebc2f6 am: 6c80cd6c am: 1a3e3059

Original change: https://android-review.googlesource.com/c/platform/build/+/2651320



Change-Id: I3fe398995536c617339b07c142dd898eafdfb01d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>