Accessibility : set ViewCompat.setAccessibilityDelegate() in a safe manner

[jd-alexander]

Related to work being carried out in #10921

Expected behavior

That when using ViewCompat.setAccessibilityDelegate there should be a check that ensures another delegate isn't currently set because future accessibility improvements could overwrite them and break existing behavior.

Actual behavior

ViewCompat.setAccessibilityDelegate is used on a View without creating any checks.

Steps to reproduce the behavior

1. Simply do a search of the repository for ViewCompat.setAccessibilityDelegate
2. You will see that no checks have been made on the current state of the Views delegate.