Comment 4 for bug 1308365

If we want to allow this feature, the call button in the dialer has to be enabled all the time, even if the number input field is empty.
A tap on the call button would pre-populate the number input field with the last dialed number and user would have to tap again to place the call.

Currently the call button is disabled because we want to avoid calls being placed by mistake if user invokes the bottom edge swipe. So, my only concern is how likely it will be that calls are placed by mistake if we allow the "press-call-twice-to-redial" functionality.