Fix missing group alertOverride recalculation

Bug: 185680162
Test: manual testing w/ telegram and whatsapp
Test: atest NotificationGroupAlertTransferHelperTest
Test: atest NotificationGroupManagerLegacyTest
(cherry picked from commit 457bab63)
(cherry picked from commit aa6a7754)
(cherry picked from commit 38d57ffe)
Merged-In: I4447810af5e2a17c3b6841dfa5cd31703e5f334d
Change-Id: I4447810af5e2a17c3b6841dfa5cd31703e5f334d