Revert^2 "Move StagedRollbackTest from postsubmit to presubmit"

This reverts commit 104d3cc4b9e8f8b8ce3d94ba607c6074c1ec81ff.

Reason for revert: change from presubmit to presubmit-large
Bug: 349693967

Change-Id: I47ea41162aea0140bc460521d0638ce9ca8a96a3
diff --git a/libprocessgroup/TEST_MAPPING b/libprocessgroup/TEST_MAPPING
index 29a9ff0..0f670ef 100644
--- a/libprocessgroup/TEST_MAPPING
+++ b/libprocessgroup/TEST_MAPPING
@@ -1,5 +1,5 @@
 {
-  "postsubmit": [
+  "presubmit-large": [
     {
       "name": "StagedRollbackTest"
     }