Freeze networkstack-aidl-interfaces to version 13.

This AIDL freeze includes a new API onReachabilityFailure added
in IIpClientCallbacks aidl and a stable parcelable to represent
the specific reachability loss information.

Bug: 204723906
Test: atest NetworkStackTests
Change-Id: I6e8935fb60a8bf131badfc8af2920734d471bc51