Merge "Add container field to flag_declarations" into main am: 6344fdf9

Original change: https://android-review.googlesource.com/c/platform/build/+/2843433



Change-Id: I14d7272d2b2551aacfb3ed01e856a6cb7fd93944
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>