Merge "update flags.mk to create one storage file per rule" into main am: 00f46433 am: b7ddda7f

Original change: https://android-review.googlesource.com/c/platform/build/+/2925170



Change-Id: Ifa37aaa750f38cdc16ab9099ce08e3f884826d66
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>