Depend on the stable AIDL version of the netd metrics interface.

We used to include the AIDL file directly, but that does not
provide useful features such as getVersion() support and is
generally not the preferred approach.

Test: builds, boots
Test: atest FrameworksNetTests android.net.cts.ConnectivityManagerTest
Change-Id: I7ca56e4b440dc2321f5a7b77bac630a48e69100a