test(input): fix tests on Firefox v93+

Since version 93, Firefox started more closely following the spec on
formatting `datetime-local` input values by removing trailing zeros from
the string representation of the value. This causes some of our tests to
fail ([example failure][1]).

For example, a value is reported by Firefox as `2009-01-06T16:25` while
the tests expect `2009-01-06T16:25:00.000`. I.e. Firefox started leaving
out seconds/milliseconds if they are zero.

According to [MDN][2], this is the correct behavior according to the
spec. Indeed the spec says that [if the value of the element is a valid
local date and time string, then it must be set to a **valid normalized
local date and time string**][3], where **valid normalized local date
and time string** is [defined as consisting of][4]:
> - A valid date string representing the date.
> - A U+0054 LATIN CAPITAL LETTER T character (T).
> - A valid time string representing the time, expressed as the
>   **shortest possible string** for the given time (e.g. **omitting the
>   seconds component** entirely if the given time is zero seconds past
>   the minute).

This commit fixes the relevant tests by explicitly specifying non-zero
values for seconds and milliseconds.

[1]: https://circleci.com/gh/angular/angular.js/3527
[2]: https://developer.mozilla.org/en-US/docs/Web/HTML/Date_and_time_formats
  #local_date_and_time_strings
[3]: https://html.spec.whatwg.org/multipage/input.html
  #local-date-and-time-state-(type=datetime-local)
[4]: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html
  #concept-datetime-local

Co-authored-by: George Kalpakas <kalpakas.g@gmail.com>