Revert "Add a holdback study for concurrent MessageQueue."

This reverts commit a08a77c89a8f94b0ce0dd86aa0ddbd3ec73de893.

Reason for revert: Some branches are not fully migrated to new aconfig storage infra.

Change-Id: I53430c96acb3f16a11429d454eb84df7c50901cb
Bug: 379351074
2 files changed