Move GtsMediaTestCases to presubmit group instead of presubmit-large

It's already running in presubmit group

Change-Id: I87943c88e081878e51c93f494a1590c50f139cc1
Test: presubmit
Bug: 270214959
diff --git a/drm/TEST_MAPPING b/drm/TEST_MAPPING
index 3642898..b2d4d6e 100644
--- a/drm/TEST_MAPPING
+++ b/drm/TEST_MAPPING
@@ -1,5 +1,5 @@
 {
-  "presubmit-large": [
+  "presubmit": [
     // The following tests validate codec and drm path.
     {
       "name": "GtsMediaTestCases",