[Connection Manager] Remove unused flags

Dead code removal. The only logical change is that now, on unbond, we
unconditionally remove the device from the allowlist, rather than
checking before doing so. But the le_impl checks for this anyway,
here: https://source.corp.google.com/aosp-master/packages/modules/Bluetooth/system/gd/hci/acl_manager/le_impl.h;l=794?q=%22acceptlist%20and%20cannot%20be%20removed%22

Bug: 272572974
Test: compiles
Change-Id: I3414348552e02426b9b210517cd5c5da862b9f78