Merge "Revert "Remove framework code that has moved to frameworks/libs/net""

core/java/android/net/LinkProperties.java

core/java/android/net/MacAddress.java

core/java/android/net/NetworkUtils.java

core/java/android/net/RouteInfo.java

...ces/core/java/com/android/server/ConnectivityService.java

tests/net/common/java/android/net/LinkPropertiesTest.java

tests/net/java/android/net/MacAddressTest.java

wifi/java/android/net/wifi/WifiConfiguration.java

wifi/tests/src/android/net/wifi/WifiConfigurationTest.java