Fix Checkstyle DateFormat Locale

[ChrisCanCompute]

Almost all callers should use getDateInstance(), getDateTimeInstance(), or getTimeInstance() to get a ready-made instance of SimpleDateFormat suitable for the user's locale. The main reason you'd create an instance this class directly is because you need to format/parse a specific machine-readable format, in which case you almost certainly want to explicitly ask for US to ensure that you get ASCII digits (rather than, say, Arabic digits).

Here, we're parsing to/from a save file, therefore should be using US Locale for storing dates.

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[AnmAtAnm]

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Review status: 0 of 1 files reviewed at latest revision, all discussions resolved.

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