[Rust] [Parquet] Fix null bitmap comparisons in roundtrip tests #18317
Description
The Arrow spec allows makes the null bitmap optional if an array has no nulls @carols10cents, so the tests that were failing were because we're comparing None with a 100% populated bitmap.
Reporter: Neville Dipale / @nevi-me
Assignee: Neville Dipale / @nevi-me
PRs and other links:
Note: This issue was originally created as ARROW-10225. Please see the migration documentation for further details.