Enabled accessibility services settings may end with a separator.

SetupWizard was adding a separator after the last service name while
building the enabled accessibility services string. This case was not
handled by the settings. Added code to handle that case since it is
possible to have not well-formed settings backed up.

bug:5098493

Change-Id: I8381872037611a7456ca31526c85effdb9949885
1 file changed