Add a releng tool for git

It supports picking a map project, selecting map file entries to
update and replacing lines in the mapfile with the new tag entry.

Bug: 328745
Change-Id: Ib1529eace4ba2c571358d1212e2c40cf00fee274
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>
21 files changed