Moving keystore2_client_tests to presubmit.

Along with this change, we are making a change to disable running
it on R and S builds - https://critique.corp.google.com/cl/673010199

Bug: 363217776
Test: Run keystore2_client_tests
Change-Id: I5b8ae71bb48033ed07d81ddb024484e7489fadc9
diff --git a/keystore2/TEST_MAPPING b/keystore2/TEST_MAPPING
index 57ce78c..f12a301 100644
--- a/keystore2/TEST_MAPPING
+++ b/keystore2/TEST_MAPPING
@@ -1,6 +1,9 @@
 {
   "presubmit": [
     {
+      "name": "keystore2_client_tests"
+    },
+    {
       "name": "keystore2_crypto_test"
     },
     {
@@ -32,9 +35,6 @@
       "name": "CtsKeystorePerformanceTestCases"
     },
     {
-      "name": "keystore2_client_tests"
-    },
-    {
       "name": "librkpd_client.test"
     },
     {