Add ability to detect cross-project patches dependency

This patch adds ability to detect cross-project patches dependency
based on 'Depends-On: https://gerrit_address/_CHANGE_NUMBER_' key
phrase in commit message.

Change-Id: I5e65aae893a60b1c35d1c34046e9c478f330a1c4
Related-bug: PROD-23448
1 file changed