By default we do not speak passwords if the user has no headset. However,
many users find this too restrictive and would like a way to enable
password announcement. While we cannot speak the passwords all the time
,to avoid leaking them, we expose a preference so each user can choose
the option that best works for him/her.
bug:5712607
Change-Id: I1a6e95c392c18dc8d7406b1cef49705756b31254
7e8dcbea65