A wrong password typed at the prompt ended the check with "Invalid backup
password", and check-androidqf skipped the backup modules. An analyst who
was handed several candidate passwords had to start the whole run again
for each one.
Ask for the password again, up to three attempts in total. A password
given with --backup-password or in the environment is not asked for
again, as before, so scripted runs fail the same way.
Fixes#979
arxhr007
706e81dff2