Use ConnectivityCheckTargetPreparer in tethering cts

This can make sure test device have wifi and mobile data connectivity before running tethering test.

Bug: 264785877
Change-Id: Iac416ca4aaccf3936134aa878b49160ca07f0486
Test: TH
diff --git a/tests/cts/tethering/AndroidTestTemplate.xml b/tests/cts/tethering/AndroidTestTemplate.xml
index 491b004..c842c09 100644
--- a/tests/cts/tethering/AndroidTestTemplate.xml
+++ b/tests/cts/tethering/AndroidTestTemplate.xml
@@ -25,6 +25,8 @@
         <option name="cleanup-apks" value="true" />
         <option name="test-file-name" value="{MODULE}.apk" />
     </target_preparer>
+    <target_preparer class="com.android.testutils.ConnectivityCheckTargetPreparer">
+    </target_preparer>
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="android.tethering.cts" />
     </test>