Made the revision history deletion page's radio buttons less confusing
 
Changed the radio button to 'Visible' and 'Hidden' from 'Yes' and 'No' and
changed the respective label messages.

Bug: 56210
Change-Id: I4263e9e15241bb705b288b2bb65f9915557bf472
Merge "Made the revision history deletion page's radio buttons less confusing   Changed the radio button to 'Visible' and 'Hidden' from 'Yes' and 'No' and changed the respective label messages."