RCFilters: Actually be consistent when storing 'highlight' state

RCFilters: Actually be consistent when storing 'highlight' state

Saved queries are storing *filter* definitions, not parameters, so
highlight state (dictating whether highlights are enabled) are supposed
to be stored as boolean.

A previous fix that was meant to make sure we store and handle all
*parameters* as strings '0' and '1' was a bit overzealous, and stored
highlight state in saved queries as '1' and '0' too. The current state
then compared that to the filter-state, which produces false/true.

This resulting in saved queries only being matched to the current
state as never true, because the comparison goes by actual obejct
key-values, not symbolic values.

Bug: T165381
Change-Id: Ifdec3a8c058a0e004304e48a857c58639928b36f