Set app_idle_constants in NetPolicyTestsPreparer is not always successful(suspect timing issue). Set app_idle_constants in AbstractRestrictBackgroundNetworkTestCase again to make sure. Bug: 115393390 Test: atest com.android.cts.net.HostsideRestrictBackgroundNetworkTests#testAppIdleMetered_whenCharging Change-Id: I41148bc7eea0825537133f0471ceefeb5b05d763