Analyze engine crash core dumps and upload the results to cloud storage

This change uses the logs_util module, which sets an environment variable
to the path of a directory that can hold logs.  After the recipe steps
finish logs_util will upload the directory contents to GCS.

The --engine-capture-core-dump flag in run_tests will write core dump logs
to this directory.

Change-Id: I6513fdd1599ac4abe2763799b7020150676431ac
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/16363
Commit-Queue: Jason Simmons <jsimmons@google.com>
Reviewed-by: Godofredo Contreras <godofredoc@google.com>
Reviewed-by: Zach Anderson <zra@google.com>