Bluetooth: Set alias name only through Rename option.

Set the alias name only when user is trying to change the
name using the Rename option of paired device.

Conflicts:
	src/com/android/settings/bluetooth/CachedBluetoothDevice.java

CRs-Fixed: 539420
Change-Id: I415b6a962d8e7884b67d37b94c04df19e2c23012