Fix TimePicker keyboard UI num digits for min

Force the minutes to always format to 2 digits. This is a temporary fix
that's not quite fully Locale aware but fixes UI issue. Will need to
refactor code to seperate Locale info, share code with non-keyboard UI
and use more native Locale functions to determine number of digits.

Test: Manual https://drive.google.com/file/d/1iabh2Zzl0YRhj17gbVKr8GvVDXEHUnWI/view?usp=sharing
Bug: 72041032
Change-Id: I0eb479b9aece4726db7bf7fba04dc50ad0f175c5