Add additional safety checking for bzr branch checks.
Review Request #12132 — Created March 10, 2022 and submitted
I was hitting an issue locally where breezy would run but was not set up
for certain operations. In this case, we were hitting an error where we
would pass the existing checks but then fail to determine the correct
branch due to the output. This change adds an additional safety check to
make sure that our regex actually found what we were looking for before
Ran unit tests and saw the error go away.