Auto detect minor version for complete partial updates am: 2a18e85a31 am: 618a20ff2b am: a536adead2

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2770381

Change-Id: If0c7a32b52d47a691cea8d967b957daa1d0e5e77
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>