Review reminders: localize strings

We have decided to wait and leave them hard-coded on purpose, for now. The future task is to make them localizable once we feel they are stable. Destials;

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I think: hold off for a little while longer

One of the strings contains "ETA", which we're likely to fully deprecate

One of the strings is using the deck name, which may be an issue:

* Long/nested decks may be badly handled
* How the notification would look, given the deck name isn't differentiated from our text
* "It's time to study "

_Originally posted by @david-allison in https://github.com/ankidroid/Anki-Android/issues/19118#issuecomment-3528781860_