Retire CbManager

It was replaced by libui.

Bug: 154346346
Test: presubmit
Merged-In: Ife562e4c2466f275567ed6dfc134ebb4f8f67aef
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: I15ad28b124100b98f8e799c3f796c5b841e932c1
7 files changed