[Thread] graduate ThreadNetworkUnitTests from postsubmit

Bug: 297729075
Change-Id: I164225791e176c13d124f6b63e1c3f1a3f3a0e34
diff --git a/thread/TEST_MAPPING b/thread/TEST_MAPPING
index 30aeca5..ec1cc08 100644
--- a/thread/TEST_MAPPING
+++ b/thread/TEST_MAPPING
@@ -4,7 +4,7 @@
       "name": "CtsThreadNetworkTestCases"
     }
   ],
-  "postsubmit": [
+  "presubmit": [
     {
       "name": "ThreadNetworkUnitTests"
     }