[Helm] Fix for passing pool config `query_parser_enabled`, `query_parser_read_write_splitting` and `primary_reads_enabled` as false

[gdubicki]

as when using default the value false was treated as, well, falsy, and the default value of true was applied...

See https://github.com/helm/helm/issues/3308 and https://stackoverflow.com/q/66265193/2693875 for more context