Actual Result:
Focus is landing on non-interactive elements after activating the 'Show a simple' Adaptive cards button.

Expected Result:
Focus should not land on non-interactive elements after activating the 'Show a simple' Adaptive cards button.

Repro Steps:

1. Open URL https://microsoft.github.io/BotFramework-WebChat/full-bundle/ in Edge browser.
2. Notice 'Upload File' and 'Send' button icons present in bottom of screen.
3. Type 'Help' in the input control at the bottom of the screen and hit enter (or click on send button).
   Content will upload, Navigate to any "Show a simple Adaptive cards " button by using Tab key and press Enter on it.
4. New data will appear.
5. Navigate to the new uploaded content by using Tab key.
6. Observe that focus is landing on the non-interactive element.

User Impact:
If focus lands on the non-interactive elements then user will get confuse and not able to understand that what action will do.

MAS Reference:
MAS 2.4.3 - Focus Order (05)

Test Environment:
OS: Windows 10
OS Build: 17134.345
OS Version: 1803
Browser: Edge

****Attachment:
MAS2.4.3_Focus is landing on non-interactive element.zip
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