Update vpnprofilestore_test to legacykeystore_test in TEST_MAPPING

The test had been changed to legacykeystore_test from ag/14968529

Bug: 192796637
Test: presubmit
Change-Id: I6519af5a204b1522f6b496f349462ee574c7e21c
diff --git a/TEST_MAPPING b/TEST_MAPPING
index f46983d..8ec213b 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -227,7 +227,7 @@
       "name": "url_device_test_tests_unit"
     },
     {
-      "name": "vpnprofilestore_test"
+      "name": "legacykeystore_test"
     }
   ]
 }