InkToolbarCustomToggleButton not showing `Pressed` state.

[Rosuavio]

Describe the bug

In CommunityToolkit/WindowsCommunityToolkit#4092 we moved to WinUI 2.6.1 and our InfiniteCanvas control uses a InkToolbarCustomToggleButton for enabling drawing with the mouse. After updating to WinUI 2.6.1, when that button is clicked it does not show it in the pressed state, but it does behave normally otherwise.

Steps to reproduce the bug

Steps to reproduce the behavior:

1. Checkout the branch for Update all relevant WinUI 2.5 revs to 2.6 CommunityToolkit/WindowsCommunityToolkit#4092
2. Open the project in visual studio
3. Build and Run Microsoft.Toolkit.Uwp.SampleApp in the project.
4. Search for and open the "InfiniteCanvas" sample in the sample app at the top right corner.
5. Click the "Hand Button".
6. See it now visually change into a clear pressed state.

Expected behavior

When the "Hand Button" it clicked its visual representation changes to show it is in a pressed state.

Screenshots

Version Info

NuGet package version:
[Microsoft.UI.Xaml 2.6.1]

Windows app type:

UWP	Win32

Windows 10 version	Saw the problem?
Insider Build (xxxxx)
October 2020 Update (19042)
May 2020 Update (19041)
November 2019 Update (18363)
May 2019 Update (18362)
October 2018 Update (17763)
April 2018 Update (17134)
Fall Creators Update (16299)
Creators Update (15063)

Device form factor	Saw the problem?
Desktop	Yes
Xbox
Surface Hub
IoT

Additional context

[beervoley]

Hi @RosarioPulella the fix was recently checked in :)

[beervoley]

@ranjeshj should I close the issue?

[michael-hawker]

@beervoley @ranjeshj is this going into a servicing release in the near future as one of our controls was effected by this upgrading for the 7.1 release of the Toolkit we're going to ship in the next month or so.