Import mobile-data-download code to AOSP. am: 5925581724 am: f359c08901 am: 4906ba1a69

Original change: https://android-review.googlesource.com/c/platform/external/mobile-data-download/+/2134626

Change-Id: I83bb14fc715917849b85e39cb42aea8f9598ad09
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>