This change fixes a keyboard trap in MaterialDatePicker where the TAB key focus was stuck within the month grid. TAB navigation is now limited to the days within the current month, allowing focus to move out of the picker.
For navigating between months, this change introduces DPAD (left/right arrow key) navigation. When on the first or last valid day of the month, the arrow keys will navigate to the previous or next month.
This CL also prevents keyboard focus from landing on disabled dates. Since GridView does not natively support skipping disabled items, custom logic has been added to find and focus on the nearest valid day during keyboard navigation.
Finally, a bug that caused focus to incorrectly jump to a previous, non-visible month during TAB navigation has been fixed. This was caused by RecyclerView's view-recycling mechanism. The solution ensures that only the currently visible month is focusable, preventing focus from moving to off-screen months.
PiperOrigin-RevId: 834271529
The issue is caused by failing to correctly take the daylight saving time into account - internally we use UTC time to represent dates, however when generating month titles we try to calculate the time difference of the UTC time and the local time, which can result in off-by-one errors when the first day of the month is also the first day of the daylight saving time, e.g., April 1, 1979 in Poland.
Fixes this by always using UTC time to generate month titles. Also clears the relevant implementation for a little bit since context is actually not required when we only need to format years and months.
Resolves https://github.com/material-components/material-components-android/issues/1935
PiperOrigin-RevId: 413505587
