Force the test app into a non-idle state.

Otherwise, the app idle state could interfere
with the test verifications.

Bug: 317204099
Test: atest ./tests/cts/hostside/src/com/android/cts/net/HostsideNetworkCallbackTests.java
Change-Id: I057546082ffc2f6f5c8da8928824a5261d0f8c7f

tests/cts/hostside/app/src/com/android/cts/net/hostside/NetworkCallbackTest.java

@@ -203,6 +203,7 @@ public class NetworkCallbackTest extends AbstractRestrictBackgroundNetworkTestCa
         // Initial state
         setBatterySaverMode(false);
         setRestrictBackground(false);
+        setAppIdle(false);
 
         // Get transports of the active network, this has to be done before changing meteredness,
         // since wifi will be disconnected when changing from non-metered to metered.