Bug 1889364 - Report java crashes from Robo Test crash log r=aaronmt

For "robo"-type ui-tests, when crash logs are found and copied to the task artifacts, parse the crash log to report a treeherder-friendly crash message.

Differential Revision: https://phabricator.services.mozilla.com/D206565

taskcluster/scripts/tests/test-lab.py

@@ -181,6 +181,8 @@ def process_results(flank_config: str, test_type: str = "instrumentation") -> No
         flank_config,
     ]
     if exit_code == 0:
+        # parse_ui_test_script error messages are pretty generic; only
+        # report them if errors have not already been reported
         command.append("--report-treeherder-failures")
     run_command(
         command,