fix(datetime): max and min works with showDefaultButtons

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
  • Some docs updates need to be made in the ionic-docs repo, in a separate PR. See the contributing guide for details.
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue URL: #26146

max and min dates are not considered when using confirmation buttons.

When no date is set, we do not filter time values based on the max/min. Only once a date has been selected should we filter the selectable time values based on the max/min.

The following check was only looking to see if value was set:

ionic-framework/core/src/components/datetime/datetime.tsx

Line 1725 in dd98677

const valueIsDefined = this.value !== null && this.value !== undefined;

This meant that if devs were using showDefaultButtons, value would not be defined until the dev clicked "Confirm". As a result, the time values were never being filtered based on max/min.

What is the new behavior?

• Time values are now filtered based on max/min when a date is selected.

Does this introduce a breaking change?

• Yes
• No

Other information