Revert "Introduce ControllerCallbackLink"

This reverts commit e521669b5d7aa6ce32bf965bd0bb9a84a2cdb19b.

Reason for revert: Another CL will be uploaded which makes the APIs public, not @SystemApi.

Bug: 122169124
Change-Id: Ie9ed1067596fe1724879e81d768ac8252eda7841
11 files changed