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: Icdede98f4b055035b09ed5b8490fe3631d424376
diff --git a/TEST_MAPPING b/TEST_MAPPING
index f53788f..defb7ee 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -11,7 +11,7 @@
       "name": "libsqlite3-sys_device_test_src_lib"
     },
     {
-      "name": "vpnprofilestore_test"
+      "name": "legacykeystore_test"
     }
   ]
 }