Move 100% of ART run-tests to test group `presubmit` in `TEST_MAPPING`.

Move remaining ART run-tests from the `postsubmit` test group to the
`presubmit` test group. This progressive rollout is to make sure
introducing ART run-tests to this test group won't disturb/break
Android presubmits.

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

  $ art/test/utils/regen-test-files
  Generated Blueprint files for 621 ART run-tests out of 920 (67%).
  Generated TEST_MAPPING entries for 379 ART run-tests out of 920 (41%):
    37 tests (10%) in `mainline-presubmit` test group.
    379 tests (100%) in `presubmit` test group.
    0 tests (0%) in `postsubmit` test group.

Test: atest --test-mapping art:presubmit
Bug: 152374989
Bug: 169310621
Change-Id: I309d3aa3ff7e36522ef445694a83c5bd95e0ef79
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 9873a6d..838960c 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -977,9 +977,7 @@
     },
     {
       "name": "art-run-test-572-checker-array-get-regression"
-    }
-  ],
-  "postsubmit": [
+    },
     {
       "name": "art-run-test-573-checker-checkcast-regression"
     },
diff --git a/test/utils/regen-test-files b/test/utils/regen-test-files
index 01cd0ee..d27225f 100755
--- a/test/utils/regen-test-files
+++ b/test/utils/regen-test-files
@@ -384,7 +384,7 @@
 # the `presubmit` test group in `TEST_MAPPING` file -- the rest will be included
 # in `postsubmit` test group.
 # This value has to be a number between 0 and 100.
-presubmit_tests_percentage = 75
+presubmit_tests_percentage = 100
 
 # Percentage of ART run-tests (among the ones expected to succeed) to include in
 # the `mainline-presubmit` test group in `TEST_MAPPING` file.