Car Bluetooth policy - option to tag a device for autoconnect

Provide an option to tag a device with a priority for auto connection.
If a device is tagged as a Primary device for example, then the auto
connect policy will always try to connect to that device first
regardless of which device connected last (which is the default policy)

Bug: b/34722344
Test: Unit test
Change-Id: Ie364a4fbf5b29bc3f6cca7433ead2ed4b4debc9e
9 files changed