ethernet: remove support for default interface ip config

Support for default IpConfiguration was removed from EthernetConfigStore
in change Ifb82a5d7fa13d17ea8fd3a42a19cd020cb95e26a. This code has since
been a noop.

Test: atest EthernetTracker
Bug: 236280707
Change-Id: I6b9a2fa1af5f6ab7454d523d28daf4ee383d3560
diff --git a/service-t/src/com/android/server/ethernet/EthernetConfigStore.java b/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
index e4445d0..17abbab 100644
--- a/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
+++ b/service-t/src/com/android/server/ethernet/EthernetConfigStore.java
@@ -18,7 +18,6 @@
 
 import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
 
-import android.annotation.Nullable;
 import android.content.ApexEnvironment;
 import android.net.IpConfiguration;
 import android.os.Environment;
@@ -47,7 +46,6 @@
 
     private IpConfigStore mStore = new IpConfigStore();
     private final ArrayMap<String, IpConfiguration> mIpConfigurations;
-    private IpConfiguration mIpConfigurationForDefaultInterface;
     private final Object mSync = new Object();
 
     public EthernetConfigStore() {
@@ -144,9 +142,4 @@
             return new ArrayMap<>(mIpConfigurations);
         }
     }
-
-    @Nullable
-    public IpConfiguration getIpConfigurationForDefaultInterface() {
-        return null;
-    }
 }
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 97d7cbf..7f353a3 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -134,7 +134,6 @@
     private int mTetheringInterfaceMode = INTERFACE_MODE_CLIENT;
     // Tracks whether clients were notified that the tethered interface is available
     private boolean mTetheredInterfaceWasAvailable = false;
-    private volatile IpConfiguration mIpConfigForDefaultInterface;
 
     private int mEthernetState = ETHERNET_STATE_ENABLED;
 
@@ -255,8 +254,6 @@
         mFactory.register();
         mConfigStore.read();
 
-        // Default interface is just the first one we want to track.
-        mIpConfigForDefaultInterface = mConfigStore.getIpConfigurationForDefaultInterface();
         final ArrayMap<String, IpConfiguration> configs = mConfigStore.getIpConfigurations();
         for (int i = 0; i < configs.size(); i++) {
             mIpConfigurations.put(configs.keyAt(i), configs.valueAt(i));
@@ -670,11 +667,6 @@
             mTetheringInterface = iface;
         }
 
-        if (mIpConfigForDefaultInterface != null) {
-            updateIpConfiguration(iface, mIpConfigForDefaultInterface);
-            mIpConfigForDefaultInterface = null;
-        }
-
         addInterface(iface);
 
         broadcastInterfaceStateChange(iface);