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

Ethernet interface naming is not consistent on Linux. While some USB
ethernet dongles show up as eth0, others might show up as usb0.

This CL changes config_ethernet_iface_regex to "*" which stands for "use
Android version specific default". The default will include both usb\d+
and eth%d named interfaces on Android U+. Android T will continue to
only include eth%d interfaces (note that the "+" is a new addition which
is highly unlikely to have any actual effect, but is more technically
correct).

Bug: 304335605
Test: TH
Change-Id: I823be8ee390cb2b6dd41b537c72ed76f5aa9e0ea
diff --git a/service/ServiceConnectivityResources/res/values/config.xml b/service/ServiceConnectivityResources/res/values/config.xml
index f30abc6..045d707f 100644
--- a/service/ServiceConnectivityResources/res/values/config.xml
+++ b/service/ServiceConnectivityResources/res/values/config.xml
@@ -194,8 +194,11 @@
         -->
     </string-array>
 
-    <!-- Regex of wired ethernet ifaces -->
-    <string translatable="false" name="config_ethernet_iface_regex">eth\\d</string>
+    <!-- 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>
 
     <!-- Ignores Wi-Fi validation failures after roam.
     If validation fails on a Wi-Fi network after a roam to a new BSSID,