1. Sometimes the print button is not enabled after selecting a printer
from the all printers activity. This was happening after a printer
was selected, we had to do a layout due to changed print attributes
(because of the new printer's capabilities), and the content did not
change. In this case we did not call the updateUi function which
enables the print button after layout is completed.
2. The accessibility code in the all printers activity was not checking
whether accessibility is on and doing some unnecessary work - not sending
events though but still. Further, the delayed runnable that was
doing the accessibilty announcements was not removed when the activity
was paused.
bug:10983508
Change-Id: Ib263116a3e21e4c75a25aa051cecbd9194417319
ebec46847d