RCFilters UI: Don't set reset button title in "restore" mode

In "clear" mode, the button only has an icon, so it needs a title.
In "restore" mode, the button has text, so it doesn't need a title,
much less a wrong one (the one from the "clear" mode).

Bonus: Remove properties from constructor that are already
set in reevaluateResetRestoreState().

Change-Id: Idab5731f51b42455801a505475002adf8437c66e