LPS-45900 Fix tests: avoid magical numbers for inherit UserRoles  using a common param variable, and expectedCount variables within test methods

Fixing a recent revert by @brianchiu to @cgoncas, showing differences between LAX CI (each test runs isolated-parallel), and Spain CI (not isolated-serial). @kristinjewell : I guess there are more cases like this (WebServerTrashTest). Let's collaborate to find them ;)