Try to fix HostsideRestrictBackgroundNetworkTests flakyness.

- If the screen is not turned on when the activity is starting, then
  that process will be in TOP_SLEEPING state and won't have temp access
  to network connectivity in restricted modes. So, add a wait time after
  turning the screen on.
- Increase the timeout for app standby wait time.

Bug: 38384021
Test: cts-tradefed run singleCommand cts-dev -m CtsHostsideNetworkTests -t \
      com.android.cts.net.HostsideRestrictBackgroundNetworkTests
Change-Id: I54563a0c8b3e783ee9279d667faa5cab529ddc7e

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

@@ -782,7 +782,7 @@ abstract class AbstractRestrictBackgroundNetworkTestCase extends Instrumentation
     }
 
     protected void assertAppIdle(boolean enabled) throws Exception {
-        assertDelayedShellCommand("am get-inactive " + TEST_APP2_PKG, 10, 2, "Idle=" + enabled);
+        assertDelayedShellCommand("am get-inactive " + TEST_APP2_PKG, 15, 2, "Idle=" + enabled);
     }
 
     /**
@@ -848,6 +848,8 @@ abstract class AbstractRestrictBackgroundNetworkTestCase extends Instrumentation
             return;
         } else if (type == TYPE_COMPONENT_ACTIVTIY) {
             turnScreenOn();
+            // Wait for screen-on state to propagate through the system.
+            SystemClock.sleep(2000);
             final CountDownLatch latch = new CountDownLatch(1);
             final Intent launchIntent = getIntentForComponent(type);
             final Bundle extras = new Bundle();