[test] fix restartServerByDeletingSSTFiles tests with checksum enabled

[m-nagarajan]

Summary

This test originally had the following flow:

• Delete the SST files.
• Restart the servers to simulate a crash and restart in the midst of SST file move.

However, this flow introduced an issue when checksum was enabled:
Graceful shutdown of the server after SST file deletion triggers a final offset sync, which throws an exception when files are missing during checksum calculations.

Modified the test to:
Stop the server -> Delete the SST files -> Start the server.

How was this PR tested?

GH CI

Does this PR introduce any user-facing changes?

• No. You can skip the rest of this section.
• [] Yes. Make sure to explain your proposed changes and call out the behavior change.

[adamxchen]

Graceful shutdown of the server after SST file deletion triggers a final offset sync, which throws an exception when files are missing during checksum calculations.

Can you add one more test (either a unit test or integ test) to test this path?

[sixpluszero]

Graceful shutdown of the server after SST file deletion triggers a final offset sync, which throws an exception when files are missing during checksum calculations.

Can you add one more test (either a unit test or integ test) to test this path?

I think the change itself is good. Regarding the suggestion by Adam, I think it is OK to have it to validate the final sync() action as you mentioned.

Nit: Is it possible to merge the non-aa test with the A/A test with some test parameters? Not necessarily need to happen in this PR if you think it is complicated but I suppose it can just be turned off by setting store to A/A = false?

[m-nagarajan]

@adamxchen @sixpluszero added more unit tests, please take another look.

[sixpluszero]

Thanks for the fix!