Add a dedicated Mainline Test Mapping group for ART

Test of *all* Mainline modules are currently configured in a single
`mainline-presubmit` Test Mapping group. This requires that users indicate the
module to install in every entry and is quite tedious.

The above approach also adds overhead due to installing, checking for, and
uninstalling Mainline modules between test module executions. This eats up
precious presubmit time and gets runtimes close to violating the SLO.

This change moves all ART Mainline module tests into a dedicated Test Mapping
group that installs the Mainline module once before executing all test modules.
This also simplifies the configuration syntax by no longer requiring brackets
that indicate the, now implicit, Mainline module.

Bug: 328102821
Test: ABTD test runs
Change-Id: If9accb54bb4d71fea834ee6fefcd4ba28c19e75e
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 9d84571..0e6a83d 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,4 +1,14 @@
 {
+  "art-mainline-presubmit": [
+    {
+      "name": "CtsPerfettoTestCases",
+      "options": [
+        {
+          "include-filter": "HeapprofdJavaCtsTest*"
+        }
+      ]
+    }
+  ],
   "presubmit": [
     {
       "name": "CtsPerfettoTestCases"