Add ACCESS_NETWORK_STATE to Tethering CTS

Add ACCESS_NETWORK_STATE to Tethering CTS because tests call to
EthernetManager#isAvailable() which is enforcing permission check
now. Without ACCESS_NETWORK_STATE, some tests will fail by lack
of permission.

Bug: 174573778
Test: CtsTetheringTest
Change-Id: I735d98527c14c12fb0f2df536cda25fdd84152f1
Ignore-AOSP-First: Security vulnerability issue should not fix on
                   aosp branch.
diff --git a/Tethering/tests/integration/AndroidManifest.xml b/Tethering/tests/integration/AndroidManifest.xml
index fddfaad..f18872a 100644
--- a/Tethering/tests/integration/AndroidManifest.xml
+++ b/Tethering/tests/integration/AndroidManifest.xml
@@ -17,6 +17,7 @@
           package="com.android.networkstack.tethering.tests.integration">
 
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
 
     <application android:debuggable="true">
         <uses-library android:name="android.test.runner" />