Bug 1042944 - added screen reader functionality to the system accessibil...

...ity component.
I remember receiving a lot of questions about these instructions. Can we add in the comment the sequence reworded? For example "the sequence is volume up+volume down, repeat the sequence 3 times". As it is, the doubt is between "up, down, down, down" and "up, down, up, down, up, down".