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

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



Change-Id: I865a01f324bec6a31a69cd980c5812fbf15a9bb3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>