Set verbosity for api_versions_trimmer_unittests

Tradefed will need the python unit test verbosity to be set as 2 to make
the test cases information could be parsing correctly.

Bug: 201273904
Test: atest api_versions_trimmer_unittests
Change-Id: I414eb9ec18dbe45e9d2360a5c1baa0bc0b315170
diff --git a/api/api_versions_trimmer_unittests.py b/api/api_versions_trimmer_unittests.py
index 4eb929e..d2e5b7d 100644
--- a/api/api_versions_trimmer_unittests.py
+++ b/api/api_versions_trimmer_unittests.py
@@ -304,4 +304,4 @@
 
 
 if __name__ == "__main__":
-  unittest.main()
+  unittest.main(verbosity=2)