Make in-memory database tests default to using random name

[philwebb]

See #7004 for background.

[snicoll]

@philwebb what did you have in mind for this. Do I understand we want to override the property when our test annotations are used? Somewhere in SpringBootTestContextBootstrapper#processPropertySourceProperties maybe?

[philwebb]

I didn't really have anything in mind, I just added the bug when #7004 was raised so we didn't forget about it. Perhaps we can add something to AutoConfigureTestDatabase?

[snicoll]

Perhaps we can add something to AutoConfigureTestDatabase?

It's already done (#7473) and it isn't the same thing IMO. If we want this to be transparent, it should apply regardless of the test slice. Arguably an integration test should have a fresh database per cached context as well. IMO the best place is the one I've referenced above but I am happy to be proven wrong.

[snicoll]

Let's stick with #7473 and let users enable that setting for integration tests as we need a way for them to opt-in.