Thread: simulate Thread on eth1 for tests

This commit changes OpenThread to simulate on eth1 instead of loopback interface.

Bug: 329188649
Test: presubmit
Change-Id: I80a2842be02c03c5987ac8be8368fa86d7c6bace
diff --git a/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java b/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
index 9370ee3..4c882d4 100644
--- a/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
+++ b/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
@@ -78,9 +78,10 @@
      */
     public FullThreadDevice(int nodeId) {
         try {
-            mProcess = Runtime.getRuntime().exec("/system/bin/ot-cli-ftd " + nodeId);
+            mProcess = Runtime.getRuntime().exec("/system/bin/ot-cli-ftd -Leth1 " + nodeId);
         } catch (IOException e) {
-            throw new IllegalStateException("Failed to start ot-cli-ftd (id=" + nodeId + ")", e);
+            throw new IllegalStateException(
+                    "Failed to start ot-cli-ftd -Leth1 (id=" + nodeId + ")", e);
         }
         mReader = new BufferedReader(new InputStreamReader(mProcess.getInputStream()));
         mWriter = new BufferedWriter(new OutputStreamWriter(mProcess.getOutputStream()));