Clean up cc_test/art_cc_test TEST_MAPPING after default update

After b/179092189, cc_test host_supported:true doesn't need TEST_MAPPING config anymore to
run in presubmit.

Change-Id: I40c912565dbaf598dbc51522ec2c784a54b0c60d
Test: presubmit
Bug: 178646865
diff --git a/libdexfile/TEST_MAPPING b/libdexfile/TEST_MAPPING
deleted file mode 100644
index a85c257..0000000
--- a/libdexfile/TEST_MAPPING
+++ /dev/null
@@ -1,20 +0,0 @@
-{
-  "presubmit": [
-    {
-      "name": "art_libdexfile_external_tests",
-      "host": true
-    },
-    {
-      "name": "art_libdexfile_external_static_tests",
-      "host": true
-    },
-    {
-      "name": "art_libdexfile_support_tests",
-      "host": true
-    },
-    {
-      "name": "art_libdexfile_support_static_tests",
-      "host": true
-    }
-  ]
-}