Use Filtered query instead of post_filter for TTMServer suggestion.

With a post_filter, query runs first and then the filter is applied
whereas with filtered query, the documents are filtered prior to
the queries.

Related doc: https://www.elastic.co/guide/en/elasticsearch/reference/current/_search_requests.html

Bug: T101236
Change-Id: I8bfeee765ad2a5ba36dc7da8402db40e9a3256a5