Add more options on RouteDiscoveryPreference

Specifically,
- mandatory features
- allowed list of packages
- package order for de-duplication

Those can be used to filter out unwanted routes or duplicate routes.

Bug: 193631822
Test: atest MediaRoute2InfoTest RouteDiscoveryPreferenceTest
Change-Id: I506e6dd2c5152d9a3127d6f34856c258bb750daa