bug: Datetime active day does not clear when pressing cancel and re-opening

### Describe the Bug

On pressing default Cancel Button in ion-datetime with ion-datetime-button and opening the ion-datetime again the date that was canceled is preselected.

### Expected Behavior

on pressing the cancel button and opening the ion-datetime again should select the date that wasn't the one that was selected on cancel

### Steps to Reproduce
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use this and click the button and select a date and then press the cancel button
now click on the button again, the date selected will be one selected when we pressed cancel not the one that is in ion-daretime-button

Reproduction: https://stackblitz.com/edit/angular-h94fr8?file=src%2Fapp%2Fexample.component.html

### Screenshots

_No response_

### Operating System

macOS

### Browser

Chrome

### Version

115.0.5790.170

### Additional Information

_No response_

Start with the ion-datetime-button, ion-modal, and ion-datetime setup in the linked StackBlitz reproduction, then reproduce the cancel-and-reopen sequence in Chrome. Trace how the default Cancel button handles the selected date when the modal uses keepContentsMounted. Done means reopening shows the date currently represented by ion-datetime-button rather than the canceled selection.

由索引模型根据 Issue 内容生成。