Add button label and mark info msgs as non-selectable

Mark info messages in AutoRevokeFragment as non-selectable, so that
Talkback does not tell the user to activate them. Add a
contentDesctiption to the uninstall button.

Fixes: 155960297
Fixes: 155958960
Test: Enable talkback, navigate to Auto Revoke fragment, highlight
remove button, and highlight info messages.

Change-Id: Id5126bc82001cb124dbd81ef07fe225dea20094f