This change only apply to the device after T. Use new bluetooth API to change bluetooth tethering settings and the new API provide the callback to to notify Tethering when bluetooth interface is ready. Tethering doesn't use bluetooth interface status change event from netlink to add/remove IpServer anymore. Tag: #feature Bug: 190438212 Test: TetheringTest Change-Id: Iae92d98d500f83b116da7282cf1130fb8fecf53d