Add CtsNNAPITestCases to mainline test mapping for neuralnetwork.

Bug: 185970126
Test: unittest
      forrest
Change-Id: I29e84af49d17a6d911c974581dedaed3a1ce4edb
diff --git a/tests/tests/neuralnetworks/AndroidTest.xml b/tests/tests/neuralnetworks/AndroidTest.xml
index 6ec4752..b89d563 100644
--- a/tests/tests/neuralnetworks/AndroidTest.xml
+++ b/tests/tests/neuralnetworks/AndroidTest.xml
@@ -19,6 +19,7 @@
     <option name="config-descriptor:metadata" key="parameter" value="not_instant_app" />
     <option name="config-descriptor:metadata" key="parameter" value="multi_abi" />
     <option name="config-descriptor:metadata" key="parameter" value="secondary_user" />
+    <option name="config-descriptor:metadata" key="mainline-param" value="com.google.android.neuralnetworks.apex" />
     <target_preparer class="com.android.compatibility.common.tradefed.targetprep.FilePusher">
         <option name="cleanup" value="true" />
         <option name="push" value="CtsNNAPITestCases->/data/local/tmp/CtsNNAPITestCases" />