contrib/release: Add a script to detect possible missing cherry picks

On release branches

BUG=b:399723498
TEST=./release/find_missing_release_cps_unittest.py && cros lint release/
TEST=./release/find_missing_release_cps.py --bug-id 400530374 --tot-milestone 136
TEST=./release/find_missing_release_cps.py --bug-id 384366187 --tot-milestone 135

Change-Id: I65fb25a3f3f74051d10dde6c59d7dab8cd27516e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/6362798
Commit-Queue: Madeleine Hardt <hardtmad@google.com>
Tested-by: Madeleine Hardt <hardtmad@google.com>
Reviewed-by: Benjamin Shai <bshai@google.com>
2 files changed