The new GenericPopupToolbarController takes by default
the popup menu controller that registered for the same
.uno:Something command, and sets ToolBoxItemBits to
ToolBoxItemBits::DROPDOWNONLY. If a different command
specified using the "Value" property - takes the popup
menu controller that registered for this command, and
sets bits to ToolBoxItemBits::DROPDOWN.

Change-Id: I75c5300bd27fcc9f618f2ee0df2aa6aefd088239
Reviewed-on: https://gerrit.libreoffice.org/20040Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>