Use datastore to determine if a checkrun rerun should trigger a presubmit or postsubmit build (#2387)

* Use GoB to determine if a checkrun should trigger a presubmit or postsubmit rerun

* Apply suggestions from code review

Co-authored-by: Casey Hillers <caseyhillers@gmail.com>

* Simplify getCommit's arguments by passing project name through slug

* Remove GoB stuff

* Use datastore instead of GoB for postsubmit check

* Fix tests and change ScheduleBuildRequest's properties map to have Objects as values instead of dynamic

* Add datastore tests

* Add logging about presubmit / postsubmit determination

* Add tests for processCheckRun

* Fix GerritCommit deserialization of committer field

* Fix gitBranch TODO in processCheckRun

* Add entity lookup methods from PR #2391

* Use entity methods

* Fix licenses test

* Rename Commit's key method, fix tests, and rewrite TODO

* Fix log message for Commit lookup

Co-authored-by: Casey Hillers <caseyhillers@gmail.com>
diff --git a/licenses/check_licenses.dart b/licenses/check_licenses.dart
index 3a9ae9c..5d0494d 100644
--- a/licenses/check_licenses.dart
+++ b/licenses/check_licenses.dart
@@ -32,7 +32,7 @@
 
 // TESTS
 String _generateLicense(String prefix) {
-  return '${prefix}Copyright (2014|2015|2016|2017|2018|2019|2020|2021|2022) The Flutter Authors. All rights reserved.\n'
+  return '${prefix}Copyright (2014|2015|2016|2017|2018|2019|2020|2021|2022|2023) The Flutter Authors. All rights reserved.\n'
       '${prefix}Use of this source code is governed by a BSD-style license that can be\n'
       '${prefix}found in the LICENSE file.';
 }