[ATest] Fix py3 unit test config

Bug: 151782999
Test: atest atest-py3_unittests(make sure executing atest-py3_unittests)

Change-Id: I29b386249dd1e3315dcbe8c111ea1e45308f82ca
diff --git a/atest/atest_unittests.xml b/atest/atest_unittests.xml
index 2f8b3af..689d21d 100644
--- a/atest/atest_unittests.xml
+++ b/atest/atest_unittests.xml
@@ -14,7 +14,7 @@
     <option name="test-suite-tag" value="atest_unittests" />
 
     <test class="com.android.tradefed.testtype.python.PythonBinaryHostTest" >
-        <option name="par-file-name" value="atest_unittests" />
+        <option name="par-file-name" value="atest-py3_unittests" />
         <option name="test-timeout" value="2m" />
     </test>
 </configuration>