Explicitly disable data backup and copy'n' paste of the password text
field.

This fixes new lint warnings and improves security. The backup would
store potentially sensitive data (host names in the DB), the
copy'n'paste feature is not required since there is a copy button.
Refactored tests, take care to reset the input fields on each test.
Tested against Android API level 17.

Required update to robotium 3.6.