Removing post submit only rule

Now that FolderIconLoadTest is no longer flakey we can remove the post submit only test stability rule and allow the tests to be run in presubmit.

Flag: None
Bug: b/319923578
Test: FolderIconLoadTest.kt
Change-Id: I115193dfef855fedbc204d0cc9d3a908b56f8eec
1 file changed