Review keyboard navigation

In !141 (merged), @pwithnall wrote:

Rows and the switches within them in the ‘Restrict Applications’ dialogue are tabbable to separately, so it takes two tab keypresses to move one row down the list. Perhaps the switch should be skipped in the keynav, and only each row be keynavable? I don’t know what the standard design pattern is for this.

This is a fair question, and even though it's what the rest of the platform does, we should at least confirm it's the desired behavior.