Test execution was broken by specifying pool.
No need to do it once we specify bot ids in included json configs.
Bug: webrtc:10047
Change-Id: Ica5b891b796eec69573cc39d1d72617a68169499
Reviewed-on: https://webrtc-review.googlesource.com/c/112129
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Commit-Queue: Artem Titarenko <artit@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25804}