Fix Collection and ConfigureIndex tests

[austin-denoble]

Problem

Currently, CollectionTest, and ConfigureIndexTest are very flakey. Collections tests take a long while to run due to the need to spin up a collection, wait until it's ready, and then creating an index and waiting until that's ready.

ConfigureIndexTest deletes the index as a part of the final @Test in the file, but it doesn't seem like the order of execution is guaranteed, so deleting an index like this may cause issues: https://www.baeldung.com/junit-5-test-order

Solution

• Update CollectionTest to create a single collection from the initial index that's shared across both tests. Previously we were creating a collection for each test, which is not ultimately necessary and is very time-consuming. Also, use assertWithRetry() to retry upserting and describing index stats. These calls seemingly have a tendency to flake when made against a newly created index. Retrying a few times if we have an error on the initial pass seems to help here.
• ConfigureIndexTest has a finally clause in the last @Test in the file deletes the index. Given we set up with @BeforeAll and the execution order is not guaranteed unless we specify, it feels like it makes more sense to clean things up in @AfterAll, which seems to resolve the issue with the test itself.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• None of the above: (integration tests)

Test Plan

Validate integration runs in CI. Runs should overall be a few minutes faster, and less prone to failing on these specific tests.

[rohanshah18]

Thanks for fixing this, I have left one comment but otherwise it looks great!