fdtrack: add a test.

Test: logcat -c; fdtrack_test; logcat -d | grep fdtrack
Change-Id: Ie1101c9cf968299ec1f03f20097a2ed27f6e15bd
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 7aeb09e..9f60ae7 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -4,6 +4,9 @@
       "name": "CtsBionicTestCases"
     },
     {
+      "name": "fdtrack_test"
+    },
+    {
       "name": "malloc_debug_system_tests"
     },
     {