Updating test in case ethernet is not available

Updating EthernetManagerPermissionTest to account for ethernet
potentially not being available. Also updating owners for this
particular file.

Bug: 218552964
Bug: 210485380
Test: atest CtsPermissionTestCases:
android.permission.cts.EthernetManagerPermissionTest

Change-Id: Ie621a17199a4079c1695d18ec8d24cba09bc4336
diff --git a/tests/tests/permission/OWNERS b/tests/tests/permission/OWNERS
index d401f0d..6b28459 100644
--- a/tests/tests/permission/OWNERS
+++ b/tests/tests/permission/OWNERS
@@ -8,4 +8,5 @@
 per-file NoAudioPermissionTest.java = elaurent@google.com
 per-file MainlineNetworkStackPermissionTest.java = file: platform/frameworks/base:/services/net/OWNERS
 per-file Camera2PermissionTest.java = file: platform/frameworks/av:/camera/OWNERS
-per-file NoRollbackPermissionTest.java = mpgroover@google.com
\ No newline at end of file
+per-file NoRollbackPermissionTest.java = mpgroover@google.com
+per-file EthernetManagerPermissionTest.java = file: platform/frameworks/base:/services/net/OWNERS
\ No newline at end of file
diff --git a/tests/tests/permission/src/android/permission/cts/EthernetManagerPermissionTest.java b/tests/tests/permission/src/android/permission/cts/EthernetManagerPermissionTest.java
index db37aa7..ef92763 100644
--- a/tests/tests/permission/src/android/permission/cts/EthernetManagerPermissionTest.java
+++ b/tests/tests/permission/src/android/permission/cts/EthernetManagerPermissionTest.java
@@ -16,9 +16,9 @@
 
 package android.permission.cts;
 
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assume.assumeFalse;
+import static org.junit.Assume.assumeNotNull;
 import static org.junit.Assume.assumeTrue;
 
 import android.content.Context;
@@ -51,7 +51,8 @@
     public void setUp() throws Exception {
         mContext = InstrumentationRegistry.getTargetContext();
         mEthernetManager = mContext.getSystemService(EthernetManager.class);
-        assertNotNull(mEthernetManager);
+        // mEthernetManager may be null depending on the device's configuration.
+        assumeNotNull(mEthernetManager);
     }
 
     private void callUpdateConfiguration() {