Merge "Revert "Revert "Add system staging dir stamp file for bazel sand...""...

Merge "Revert "Revert "Add system staging dir stamp file for bazel sand..."" into main am: 8cad379e

Original change: https://android-review.googlesource.com/c/platform/build/+/2686910



Change-Id: I03200fefa15b397a3980b90acf54d5fa676346c9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>