Kibana version:
7.9.1

Describe the bug:

When editing an v2 index template under certain conditions it can't be saved

Steps to reproduce:

1. Create a component templates
2. Create a v2 Index Template
3. Add component template(s)
4. Save
5. Edit the v2 Index Template just created
6. Remove a component template
7. Click Next to the final screen
8. Save.
   The save button just spins saying "Saving" and will continue like this forever.

Expected behavior:

Saving should work

Screenshots (if relevant):

Errors in browser console (if relevant):