CMFM: Wait indefinitely on privileged console allocation

Wait indefinitely if a privileged console is being allocated. Wait for
the user response to SuperUser or SuperSu prompt (or whatever it is).

Change ShellConsole.this access to a private variable in methods of ShellConsole

Change-Id: I6752fe8bcd0de3aa6478ad97fb84c9ac8697a970
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>