Merge "aflags: show staged values for each flag." into main am: c7704f16

Original change: https://android-review.googlesource.com/c/platform/build/+/3000279



Change-Id: I492befcbc80029416166455b38c68b4a9a26658f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>