* aws_kms: handle updated policy format+cleanup
- create slightly updated policy in that handles lists instead of a single string; the previous version's policy was being rejected if the key was new enough to have the updated base policy.
- removed `dry_run` conditionals, not committing the policy anyhow.
- return the policy in the return data. Leaving undocumented for now.
- update exception handling: don't rethrow in `do_grant`, don't pass anything to `format_exc`.
* whitespace/indent fail
* fix list-plus-brackets
* str and list fixes for ryansb
* port changes from #31667 over, better listification
8ab4412684