Fix Group Helper tests to have appropriate counts

CheckAutogroupBeforePost reduces the number of calls to
addAutoGroup, so the tests that check the exact number of calls need to
reflect that change. Some were missed when the code was initially added.

Bug: 340665334
Test: atest GroupHelperTest
Flag: android.app.Flags.FLAG_CHECK_AUTOGROUP_BEFORE_POST
Change-Id: I1949113a88a1406053fde2606b41030e9d86f36f