Remove the local cached name

1. Use BluetoothDevice.getAliasName() to get the cached name instead of
   use mName that is local cached.
2. Add test to verify following situations:
   1. Verify when alias name is not null return alias name otherwise return
   address.
   2. Verify the BluetoothDevice.setAlias() will be called when set
   name is not null.

Bug: 112517004
Test: make -j42 RunSettingsLibRoboTests ROBOTEST_FILTER=CachedBluetoothDeviceTest
Change-Id: Ib4f002da6ceac8e8e562bf17a167a0c9ae6a3953