[automerge] Add EnabledSupplier in ManifestFileGroupPopulator 2p: a8939013f9

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/mobile-data-download/+/21019686

Bug: 265797474
Change-Id: I918531d763bcc588dff493e05e7a83a6d78feadb