Defer sendDeviceStateChanged until SIM config loaded

When a sim is inserted, the service state will change before all the
data is fully available. To prevent the headset from seeing bad data,
wait until the sim config is fully loaded before calling
sendDeviceStateChanged.

Change-Id: I49831b8b1e494b2263cbc543c187b170faaaaca0
Fixes: 37301718
Test: manual
(cherry picked from commit a49c40ce)