EthernetDataTracker: indicate link up based on flags

Indicate link up state based on flags/interface up, and not on IP address.
This is for ethernet interfaces that already exists.

Change-Id: Ib342d519c483bbb2dfa08cfac2c0c1a288cee7c0
Signed-off-by: Vishal Mahaveer <vishalm@ti.com>

Author: vishalmti

core/java/android/net/EthernetDataTracker.java

@@ -223,7 +223,7 @@ public void startMonitoring(Context context, Handler target) {
                     mIface = iface;
                     mNMService.setInterfaceUp(iface);
                     InterfaceConfiguration config = mNMService.getInterfaceConfig(iface);
-                    mLinkUp = config.isActive();
+                    mLinkUp = config.hasFlag("up");
                     if (config != null && mHwAddr == null) {
                         mHwAddr = config.getHardwareAddress();
                         if (mHwAddr != null) {