Add DefGrantPoligyTest to TEST_MAPPINGS

Test: presubmit
Change-Id: I8794ef047121c9480f12bbfedc94fb11da3209b2
diff --git a/services/core/java/com/android/server/pm/permission/TEST_MAPPING b/services/core/java/com/android/server/pm/permission/TEST_MAPPING
index 610c82f..c7e7c1d 100644
--- a/services/core/java/com/android/server/pm/permission/TEST_MAPPING
+++ b/services/core/java/com/android/server/pm/permission/TEST_MAPPING
@@ -60,5 +60,10 @@
                 }
             ]
         }
+    ],
+    "imports": [
+        {
+            "path": "vendor/xts/gts-tests/tests/permission"
+        }
     ]
 }