Cleaning up deprecate_flags_and_settings_resets

This flag has been released in 24Q4 and can be cleaned up.
Following go/android-flags-guidelines#how-to-delete-a-flag

Bug: 397017037
Test: TH
Flag: EXEMPT cleaning flag
Change-Id: Ia3a91f40693d99fa360140d8af19b036d1e4a1b1