[SB][Screen Chips] Update red color for screen chips to be brighter.

Also updates our GM_red_600 token to be GM_red_800 (the actual color is
the red 800 color, the token was misnamed).

Fixes: 357061027
Bug: 332662551
Flag: com.android.systemui.status_bar_screen_sharing_chips
Test: start screen record, cast, or share -> verify chip color in light
and dark mode

Change-Id: I217aea653b7abed2c053099a7d646ab0300710c9