Add support to pass agg_hash to dlrn report playbook
Add support to pass agg_hash to dlrn report playbook

With component based repos we want to report result
based on aggregate hash instead of commit+distro hash.
This patch adds agg_hash to dlrn api report playbook.

Also do not pass commit_hash, distro_hash and agg_hash
to dlrn_api module if they are not defined.

Change-Id: I2e78b2e11be9c6342a8fd4dffa7faea43003e66c

rdo-infra/weirdo