MediaRouter2: Fix routes IDs in RoutingSessionInfo

This CL fixes the issue that RoutingSessionInfo#getSelectedRoutes
return improper route IDs when it is recreated.

To ensure provider ID related feature, another test is added.
Since RoutingSessionInfo#setProviderId is a hidden method, the test
is not added to CTS.

The reason for moving "updating route ID logic" into Builder is from
considering use cases.
The original ID of the route is only checked when the provider ID is
set and a route is added to or removed from a RoutingSessionInfo,
which is very rare case.

This CL also fixes the issue that didn't release the previous routing
session when transfer.

Bug: 150666870
Bug: 150751854

Test: atest mediaroutertest
Change-Id: Ic05c11ebf43562b44214eb661c8b9c106f1c9d3e