Don't use PhonePolicy on automotive builds

Automotive builds provide their own connection policy code which
conflicts with the code in PhonePolicy. The overlay used to disable
PhonePolicy is not available outside of the Bluetooth stack anymore as
its not overlayable.

Tag: #stability
Bug: 218408055
Test: make -j; -- make sure phone policy does not come up on AAOS builds
Change-Id: Ic731c5cc698e5dbb589b5d56df89f7876f726d03