This will be used in the following change to split
merge_target_files into a collection of smaller
more-focused scripts.
Bug: 221858722
Test: m otatools; Use to create merged builds
Change-Id: Ie01dac81c5f9f28f1e0fe037259eabd2478e60b6
(cherry picked from commit 2b0b9ca1b7)
Daniel Norman