generic_rrt: Add clear TPM test

Some projects met "TPM is not cleared" error at factory finalize step.
Add clear TPM to test this flow for multiple iterations.

BUG=chrome-os-partner:36508
TEST=Manual

Change-Id: I5129f33eda1a9f59ce160909bab21f29382c9698
Reviewed-on: https://chromium-review.googlesource.com/277977
Reviewed-by: Bowgo Tsai <bowgotsai@chromium.org>
Commit-Queue: Bowgo Tsai <bowgotsai@chromium.org>
Tested-by: Bowgo Tsai <bowgotsai@chromium.org>
1 file changed