add TRANSPORT_THREAD and freeze DnsResolver AIDL interfaces to v11

1. Adds `TRANSPORT_THREAD` to IDnsResolver.aidl as this is required
   per its documentation
2. Freeze the DnsResolver AIDL API to V11 so that the Connectivity
   module can refer to the new DnsResolver API.

Bug: 262683651
Test: `m` and unit tests
Change-Id: I572e7bad8a28d6760f4d3f23e0aaf4b77c3a604e