Description

The previously applied footer padding value is not cleared after removing the footer view from Shell flyout.

Steps to Reproduce

1. Run the HostApp.
2. Goto ShellFlyoutContent sample.
3. Click on Toggle Header/Footer View button to add the footer.
4. Open the flyout and observe the footer is occupying some space in the bottom.
5. Click on Toggle Header/Footer View button to remove the footer.
6. Open the flyout again and observe the padding value is retained in the bottom.