[SB][Chips] Localize the screen record 3-2-1 countdown text.

Not all locales use Arabic numerals, so we should use NumberFormat to
correctly format the 3-2-1 countdown to the right numeric system.

Fixes: 412426285
Flag: com.android.systemui.status_bar_chips_modernization
Test: Use locale with non-Western Arabic numeral system then start
screen record -> verify 3-2-1 countdown is in that numeral system

Change-Id: Ie665b012a6c77d8127c1b6e6cb3a7451d811179a