Revert "Include both eth%d and usb%d ethernet interfaces on U+"

This reverts commit 11eac8e12b30643881951b640da0db9cbe78d3c7.

Reason for revert: there are devices in the field using usbX interfaces for tethering

Change-Id: I7bbcbb703294de1c9dd3e0390bc8ad28aa350ef6
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 01b8de7..48e86d8 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -48,7 +48,6 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.IndentingPrintWriter;
-import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.NetdUtils;
 import com.android.net.module.util.PermissionUtils;
 import com.android.net.module.util.SharedLog;
@@ -238,18 +237,7 @@
         mDeps = deps;
 
         // Interface match regex.
-        String ifaceMatchRegex = mDeps.getInterfaceRegexFromResource(mContext);
-        // "*" is a magic string to indicate "pick the default".
-        if (ifaceMatchRegex.equals("*")) {
-            if (SdkLevel.isAtLeastU()) {
-                // On U+, include both usb%d and eth%d interfaces.
-                ifaceMatchRegex = "(usb|eth)\\d+";
-            } else {
-                // On T, include only eth%d interfaces.
-                ifaceMatchRegex = "eth\\d+";
-            }
-        }
-        mIfaceMatch = ifaceMatchRegex;
+        mIfaceMatch = mDeps.getInterfaceRegexFromResource(mContext);
 
         // Read default Ethernet interface configuration from resources
         final String[] interfaceConfigs = mDeps.getInterfaceConfigFromResource(context);
diff --git a/service/ServiceConnectivityResources/res/values/config.xml b/service/ServiceConnectivityResources/res/values/config.xml
index 045d707f..f30abc6 100644
--- a/service/ServiceConnectivityResources/res/values/config.xml
+++ b/service/ServiceConnectivityResources/res/values/config.xml
@@ -194,11 +194,8 @@
         -->
     </string-array>
 
-    <!-- Regex of wired ethernet ifaces. Network interfaces that match this regex will be tracked
-         by ethernet service.
-         If set to "*", ethernet service uses "(eth|usb)\\d+" on Android U+ and eth\\d+ on
-         Android T. -->
-    <string translatable="false" name="config_ethernet_iface_regex">*</string>
+    <!-- Regex of wired ethernet ifaces -->
+    <string translatable="false" name="config_ethernet_iface_regex">eth\\d</string>
 
     <!-- Ignores Wi-Fi validation failures after roam.
     If validation fails on a Wi-Fi network after a roam to a new BSSID,