PM-635 introduced different flags to ban failing tests running in the sharding.yml suite with the embedded router enabled. All the flags have the same purpose and were merely a way to categorize the tests.

This creates confusion for other engineers who are not familiar with the details of PM-635 and don't know which flag to use when they encounter failures with the embedded router.

The goal of this ticket is to consolidate all temp_disabled_embedded_router_* flags into a single flag for disabling tests that run in the sharding suite with the embedded router.