Rework on the text button use case to pass [b/347102786](https://b.corp.google.com/347102786),
After talking with the tester, it seems like there isn't an issue with the A11y of the text button, rather just how the test case is set up. In order for the text case to pass, there needs to be real time feedback of an action that is done by pressing the text button (think of a dialog popup, or form submission notification).
So I rewrote the test case to mimic a simple form with a submit button that once submitted, will let the user know it is submitted with a snack bar notification. https://screencast.googleplex.com/cast/NTM0ODc1NDIxMDE2MDY0MHwzYWI4MTZhMS1hMA
Adds Semantic Widget to wrap the contents of each page's AppBar title attribute and adds header: true and headingLevel: 1 as Semantic attributes so the content of the title is compiled as an h1 tag to meet accessibility guidelines that each page must have a h1 tag present. Also updates the test cases for the home page and each use case page to check for its respective h1.
[Before Screenshot - Accessibility Assessments Home Page](https://screenshot.googleplex.com/4i9LuiGwvLnEcZ8)
[Before Screenshot - Checkbox List Title -- note: each use case page is missing an h1](https://screenshot.googleplex.com/3qQjfqvAMTehRsm)
[After Screenshot - Accessibility Assessments Home Page](https://screenshot.googleplex.com/APSJJXBmwNBP35m)
[After Screenshot - Checkbox List Title-- note: change is similar across each Accessibility use case page](https://screenshot.googleplex.com/6EGgZnTusEgeN5L)
Fixes b/338035526