Testing performed after [0] was merged revealed 2 issues:
1) The name of the operator should be 'DeckhandRetrieveRenderedDocOperator'
instead of 'DeckhandValidateSiteDesignOperator'.
2) We should be using task_id instead of subdag name to identify
the task which requires retrieval of revision id
This patch set is meant to correct the behavior
[0] https://review.gerrithub.io/#/c/402347/
Change-Id: I4498cd37a1aa8f2b16e17b2a3e6d3e41b2ee47b1
7046ad34ed