"20" is default pagination for Subscriptions, but cannot actually be re-selected
Description of problem:
On the Subscriptions page, the default pagination is 20. However, if user changes it and tries to go back... well, their only options are "5, 10, 15, 25, 50".
Version-Release number of selected component (if applicable):
6.4.0 snap 10
Steps to Reproduce:
1. Upload a manifest to an Org (presumably a manifest with many subs) and navigate to Subscriptions.
2. Scroll to bottom of list, and note the default pagination.
3. Select a different pagination option and reload
4. Attempt to choose 20 again
"20" is not an option in the selector.
Obvious workaround is to navigate back to the subscriptions page via the UI.
But this is just silly.
I am not sure where in the UI, if anywhere, this is also a problem.