Problem description:
If the refresh interval of a widget is updated via the "Refresh interval" pop-up menu, the actual change takes place instantly, but in the "Refresh interval" pop-up menu it is reflected only after the dashboard is opened in Edit mode and saved.

Steps to reproduce:
1 - Create a new dashboard.
2 - Add a Graph (classic) widgets to the dashboard with "10 minutes" refresh interval.
3 - Save the dashboard.
4 - Click on the "Adjust widget refresh interval" button and attempt to set the refresh interval to "10 seconds".
5 - Click on the "Adjust widget refresh interval" button again to verify that the refresh period has been changed.

Result 1: the "Refresh interval" pop-up menu shows that the refresh interval is still set to "10 minutes", but actually the widget is refreshed each 10 seconds.

6 - Click on Edit dashboard and then on Edit widget buttons.
7 - Set the refresh interval to "2 minutes" and save the changes made to widget and the dashboard.
8 - Click on the "Adjust widget refresh interval" button again to verify that the refresh period has been changed.

Result 2: the "Refresh interval" pop-up menu shows that the refresh interval is now set to "10 seconds".

Expected result: the changes of the refresh interval should be reflected in the "Refresh interval" menu right after they were made.

Example: