Fix for BluetoothAdapter.getAddress() when BT is off on some devices

There are two problem, 1.If we have wrong bluetooth address in
global settings db, we never will update it 2. We need enable bluetooth
to get the bluetooth address for some devices. For 1, we fix it by add
a valid flag in global setting db, this flag will be set when we stored
correct address and name to db. We only load the name and address from
global setting db when this valid flag is set during power up.
For2. we will read BT address after bluetooth is at ON state.
bug 7440409

Change-Id: Ic4740b3f0b2fcd214c7ca8393f7331c140eec66d