Whitelist parameters in prebuildTransactions
Whitelist parameters in prebuildTransactions

Summary:
This is D6553 (which was accepted, and I haven't changed any code after acceptance). However when I did 'arc land' I had conflicts with master, so I rebased. The conflict was around the parameters object below - Arik and I had both whitelisted different sets of parameters, so I combined them during the rebase.

However, post-rebase arcanist is no longer associating this branch with D6553. So I'm pushing up a new one (I've confirmed the code looks right and there aren't any test regressions).

Reviewers: mark, arik

Reviewed By: arik

Subscribers: ben

Differential Revision: https://phabricator.bitgo.com/D6575

BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS