Fix ANR in Settings and Phone app.

When we have a lot of devices paired and try to enable bluetooth,
loadBondState will take a some time. During this all UUIDs would
have been registered and we would send out the Bluetooth On intent.
When Settings apps or phone app gets the Bluetooth On intent, they
try to initialize state. However, the enable Thread in Bluetooth Service
is still initializing internal state in loadBondState leading to
ANRs and deadlocks. So register SDP records as the last step of enable Thread.

Change-Id: Iaa0a773e31b9d269f4c56c4f975a0e2973e02d6e