[Rust] Reduce Rc usage

[asfimport]

Follow up of ARROW-7560

Reporter: Gurwinder Singh / @95th
Assignee: Gurwinder Singh / @95th

PRs and other links:

• GitHub Pull Request #6263

_{Note: This issue was originally created as ARROW-7659. Please see the migration documentation for further details.}

[asfimport]

Neville Dipale / @nevi-me:
Issue resolved by pull request 6263
#6263