Move test_mainline_modules to AndroidTest.xml

When an AndroidTest.xml is used, configuration needs to be in the
AndroidTest.xml file, not in the Android.bp.

This currently causes tests not to be run in TEST_MAPPING as they should
be.

Test: TH needs to test
Bug: 187935317
Change-Id: Ie0aca0c64646825175769cd375bcecf65de4b4c8
diff --git a/tests/common/AndroidTest_Coverage.xml b/tests/common/AndroidTest_Coverage.xml
index 577f36a..7c8e710 100644
--- a/tests/common/AndroidTest_Coverage.xml
+++ b/tests/common/AndroidTest_Coverage.xml
@@ -18,6 +18,7 @@
     </target_preparer>
 
     <option name="test-tag" value="ConnectivityCoverageTests" />
+    <option name="config-descriptor:metadata" key="mainline-param" value="CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex" />
     <test class="com.android.tradefed.testtype.AndroidJUnitTest" >
         <option name="package" value="com.android.connectivity.tests.coverage" />
         <option name="runner" value="androidx.test.runner.AndroidJUnitRunner" />