Run a subset of tests on the Flutter test registry

[kenzieschmoll]

These tests were disabled in https://github.com/flutter/tests/pull/406 due to the long runtime. In the meantime, we should select a set of tests that are representative of things we'd like to run on each flutter commit (inspector tests, service tests, others?). Once we have modified our flutter customer test script to run this subset of tests we can re-enable our test registry entry by reverting https://github.com/flutter/tests/pull/406.