Merge "Extract class MetadataDb to a separate python library so it can be used...

Merge "Extract class MetadataDb to a separate python library so it can be used in notice files generation." into main am: eda61c1a

Original change: https://android-review.googlesource.com/c/platform/build/+/3277554



Change-Id: I9307958585033ec6542916e47f4d8a265c9db401
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>