Fix Save button appearing on changing default search filter

Steps to reproduce:

1. In Web UI, navigate to either Search or Asset Search from Drawer
2. If not already present, create a saved search by applying filter(s) and clicking the Save As button in the top right (refresh the page following this step)
3. Navigate to a custom search from the Search Filters dropdown at the top
4. Navigate back to the default search (named SEARCH FILTERS)
5. Apply any filter setting from the nuxeo-search-form below

Expected: No buttons except for "Save As" should appear when making changes to the default search

Actual: The "Save" button (shown when adding filters to a saved search) appears at the top right, which prompts to save as new search (identically to 'Save As' button)