[VPAT][A11y][a11y-app] the ci of a11y_assessment app doesn't catch all text contrast violation #172993
Description
b/429353676
b/429090526
b/428638407
Run the https://github.com/flutter/flutter/tree/master/dev/a11y_assessments and go to respective page in the screenshots
Foreground text color: #FFFFFF
Background color: #4CAF50
Contrast ratio: 2.77:1
Foreground text color: #65558F
Background color: #CFBDFE
Contrast ratio: 3.80:1
The ci should have caught these text contrast violation, we should investigate why and also fix these violation