Merge "add default path to flag bp files in mainline module" into main am:...

Merge "add default path to flag bp files in mainline module" into main am: 4da7b0f8 am: 7db4aaea

Original change: https://android-review.googlesource.com/c/platform/build/+/3291667



Change-Id: I0e26db682391c166c9c9e89fd7eefadb25158ade
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>