Adapt to renamed Account.Id.parse method

In [1] the method `parse` was renamed to `tryParse`, and its return
type changed to Optional<Id>.

[1] https://gerrit-review.googlesource.com/c/gerrit/+/156872

Change-Id: Ic0e503afd61328a43715a74d22b89914305b3a4e
4 files changed