Toggling visibility of date range picker leads to memory leak

[gokulb97]

When toggling the date range picker the component using *ngIf cause memory leak.
This issue occurs when we open the calendar popup and hide the date range picker.

Here is example: https://stackblitz.com/edit/stackblitz-starters-jsvxq1

1. On initial load there was only one instance of date range picker component
   

2. After selecting dates and toggle visibility multiple times the no of instances increased
   

Note: The date range picker is not destroying only if user open calendar popup. I suspect this is due to event listeners attached to the apply and cancel button in the calendar popup.

We have multiple forms contains date range picker and other inputs in a page, which causing large memory leaks.