[pickers] Enable mask by default when using ampm=true

[alexfauquette]

Fix #4488

The default value of disableMaskedInput was set to true if the component used ampm=true

This sounds like it has been partially fixed because acceptRegex and inputFormat were adapted to accept meridian time. Only the mask was not adapted. Now it's done and tested

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	259.2	684.3	403.2	425.76	159.346
Sort 100k rows	ms	472.4	1,013.5	696.3	801.72	194.989
Select 100k rows	ms	124.6	271	219.9	200.36	63.614
Deselect 100k rows	ms	108.5	213.7	199.5	185.78	39.346

Generated by 🚫 dangerJS against 3ab02ab

[flaviendelangle]

Seems to work as expected