Core: The `index.query.parse.strict` setting also fails if queries refer to unmapped fields.

Also the percolator and filter parsing for aliases enforce strict query parsing

Strict parsing for percolator and filter alias parsing is only enforced on indices created after to upgrade to `1.4.0`

PR for #6664
Should it be a boolean instead and reset to `indexQueryParser.defaultDisallowUnmappedFields()`?