Add standalone ART gtests to `TEST_MAPPING` group `mainline-presubmit`.

Output of `art/test/utils/regen-test-files`:

  $ art/test/utils/regen-test-files
  Generated Blueprint files for 626 ART run-tests out of 930 (67%).
  Generated TEST_MAPPING entries for 376 ART run-tests out of 930 (40%):
    376 ART run-tests (100%) in `mainline-presubmit` test group.
     19 ART gtests (100%) in `mainline-presubmit` test group.
    376 ART run-tests (100%) in `presubmit` test group.
     19 ART gtests (100%) in `presubmit` test group.
      0 ART run-tests (0%) in `postsubmit` test group.

Test: Rely on TreeHugger presubmits
Bug: 178703264
Bug: 152379281
Change-Id: I84da85e33c7ac1e44361bbb0b3bfa399ceab9b2f
diff --git a/TEST_MAPPING b/TEST_MAPPING
index c561da1..6470ace 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1128,6 +1128,63 @@
     },
     {
       "name": "art-run-test-963-default-range-smali[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_cmdline_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_compiler_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_dex2oat_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_dexdump_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_dexlist_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_dexoptanalyzer_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libartbase_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libartpalette_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libartservice_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libarttools_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libdexfile_support_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libdexfile_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_libprofile_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_oatdump_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_odrefresh_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_profman_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_runtime_compiler_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_runtime_tests[com.google.android.art.apex]"
+    },
+    {
+      "name": "art_standalone_sigchain_tests[com.google.android.art.apex]"
     }
   ],
   "presubmit": [
diff --git a/test/utils/regen-test-files b/test/utils/regen-test-files
index ed8b73b..2ce8d6f 100755
--- a/test/utils/regen-test-files
+++ b/test/utils/regen-test-files
@@ -644,10 +644,12 @@
     run_test_module_names = [ART_RUN_TEST_MODULE_NAME_PREFIX + t for t in art_run_tests]
 
     # Mainline presubmits.
-    mainline_presubmit_run_tests = [t + "[com.google.android.art.apex]"
-                                    for t
-                                    in run_test_module_names[0:num_mainline_presubmit_run_tests]]
-    mainline_presubmit_tests_dict = [{"name": t} for t in mainline_presubmit_run_tests]
+    mainline_presubmit_run_tests = run_test_module_names[0:num_mainline_presubmit_run_tests]
+    mainline_presubmit_tests = mainline_presubmit_run_tests + art_gtest_module_names
+    mainline_presubmit_tests_with_apex = [t + "[com.google.android.art.apex]"
+                                          for t
+                                          in mainline_presubmit_tests]
+    mainline_presubmit_tests_dict = [{"name": t} for t in mainline_presubmit_tests_with_apex]
 
     # Presubmits.
     other_presubmit_tests = [
@@ -940,6 +942,7 @@
     for (num_tests, test_kind, tests_percentage, test_group_name) in [
         (num_mainline_presubmit_run_tests, "ART run-tests", mainline_presubmit_tests_percentage,
          "mainline-presubmit"),
+        (len(art_gtest_module_names), "ART gtests", 100, "mainline-presubmit"),
         (num_presubmit_run_tests, "ART run-tests", presubmit_tests_percentage, "presubmit"),
         (len(art_gtest_module_names), "ART gtests", 100, "presubmit"),
         (num_postsubmit_tests, "ART run-tests", postsubmit_tests_percentage, "postsubmit"),