Test app standby APIs

Also revert a workaround for incorrect state in
AppIdleHistory.

Bug: 69867516
Bug: 63527785
Test: cts-tradefed run cts-dev -m CtsAppUsageHostTestCases

Change-Id: If3edb88f12d949ab78788e5ea27f0aee76cc4235

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

@@ -139,8 +139,6 @@ abstract class AbstractRestrictBackgroundNetworkTestCase extends Instrumentation
             enableLocation();
         }
         mSupported = setUpActiveNetworkMeteringState();
-        // TODO: Remove this once b/69867516 is fixed.
-        executeShellCommand("am set-standby-bucket " + TEST_APP2_PKG + " 12");
         setAppIdle(false);
 
         Log.i(TAG, "Apps status on " + getName() + ":\n"