Comment 2 for bug 1705087

Actually the stable/ocata branch upstream has this code as you suggest, with MANILA_QUOTA_FIELDS defined as a tuple. In stable/pike it was changed to a tuple:

commit fae241c1614de093636379fb306fa3242b45fe1a
Author: Valeriy Ponomaryov <email address hidden>
Date: Wed May 17 17:46:14 2017 +0300

    Fix compatibility with Horizon

    One of recent commits [1] to Horizon project broke compatibility
    with Manila UI project. So, update it.

    [1] I41cdabde477d87aa8b35d1c908e18a69454286c3

Your deployment apparently actually had stable/pike manila-ui code mixed with stable/ocata horizon code and you fixed it by effectively reverting the above commit.

Good detective work, and glad you got a fix, but I don't think there is anything for us to do upstream where we have appropriate manila-ui code on each of these branches for the corresponding base horizon package.