Change default value from true to false in CTS for isPreferentialNetworkServiceEnabled Test: atest DevicePolicyManagerTest#testSetGetPreferentialNetworkServiceEnabled; atest MixedManagedProfileOwnerTest#testSetPreferentialNetworkServiceStatusLogged; atest MixedManagedProfileOwnerTest#testSetGetPreferentialNetworkServiceStatus Bug: 187771747 Change-Id: Ia053fc2146f55c390cb0e4b9c4ccff48fdcbda91