[SB][Screen Chips] Don't require minWidth for the countdown chip.

We previously required all chips to have a minWidth for accessibility
since all chips were tappable. The countdown chip isn't tappable, so we
don't need to enforce that minWidth requirement for the countdown chip
(or for any non-tappable chip).

Bug: 353485675
Bug: 332662551
Flag: com.android.systemui.status_bar_screen_sharing_chips

Test: Start screen record -> verify countdown chip is smaller
Change-Id: Ifb1420e408432ed81c9f53b328d4d2882369c295