CTS test ConnectivityDiagnostics via CarrierPrivilegesTracker.

This change adds a CTS test for ConnectivityDiagnostics using
CarrierPrivilegesTracker to receive permissions for
ConnectivityDiagnostics callbacks.

Specifically, the test provides CarrierPrivileges to the test package
(android.net.cts) for the active subscription via Carrier Configs
overrides. CarrierPrivilegesTracker listens to the Carrier Configs
change and matches the loaded certificate with the test package, then
includes the test package UID as an administrator for the Network in
ConnectivityService. Then, a ConnectivityDiagnosticsCallback is
registered and receives a ConnectivityReport on register for the active
subscription.

Bug: 148032944
Bug: 151332031
Test: atest ConnectivityDiagnosticsManagerTest
Change-Id: Iee8a428ada0b6e2127410267a13c3b688df83e6d
Merged-In: Iee8a428ada0b6e2127410267a13c3b688df83e6d
1 file changed