target_file_size_base does not seem to take effect if done after database has some data

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### Expected behavior
If I change target_file_size_base, new data should be written with the newer value.

### Actual behavior
Seems like the file sizes stay the same as before.

### Steps to reproduce the behavior

1. Open a db with target_file_size_base = 20 MB, write some data into it (say 2 GB)
2. Notice that the sst files are 20 MB each.
3. Now close the DB, and reopen with target_file_size_base = 50 MB, write another 2 GB of data.
4. Notice how sst files are still 20 MB each.

While we are at this, I would also like to confirm the behavior of changing other params after the DB has some data (like block_size for example)