[Discover] Fix 0 filters applied state (#5733) (#5742)

* [Discover] Fix 0 filters applied state

* Adds changelog
* fixes unit test


---------

Signed-off-by: Ashwin P Chandran <ashwinpc@amazon.com>
(cherry picked from commit f8ee03a)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

src/plugins/discover/public/application/components/sidebar/discover_field_search.test.tsx

@@ -83,7 +83,7 @@ describe('DiscoverFieldSearch', () => {
     btn = findTestSubject(component, 'toggleFieldFilterButton');
     const badge = btn.find('.euiNotificationBadge');
     // available filters
-    expect(badge.text()).toEqual(NUM_FILTERS.toString());
+    expect(badge.text()).toEqual('0');
     // change value of aggregatable select
     const aggregatableButtonGroup = findButtonGroup(component, 'aggregatable');
     act(() => {
@@ -114,10 +114,10 @@ describe('DiscoverFieldSearch', () => {
     const btn = findTestSubject(component, 'toggleFieldFilterButton');
     btn.simulate('click');
     const badge = btn.find('.euiNotificationBadge');
-    expect(badge.text()).toEqual(NUM_FILTERS.toString());
+    expect(badge.text()).toEqual('0');
     const missingSwitch = findTestSubject(component, 'missingSwitch');
     missingSwitch.simulate('change', { target: { value: false } });
-    expect(badge.text()).toEqual(NUM_FILTERS.toString());
+    expect(badge.text()).toEqual('0');
   });
 
   test('change in filters triggers onChange', () => {

src/plugins/discover/public/application/components/sidebar/discover_field_search.tsx

@@ -273,7 +273,7 @@ export function DiscoverFieldSearch({ onChange, value, types }: Props) {
                 hasActiveFilters={activeFiltersCount > 0}
                 aria-label={filterBtnAriaLabel}
                 data-test-subj="toggleFieldFilterButton"
-                numFilters={NUM_FILTERS}
+                numFilters={activeFiltersCount} // {NUM_FILTERS} https://github.com/opensearch-project/oui/issues/1219
                 onClick={handleFacetButtonClicked}
                 numActiveFilters={activeFiltersCount}
                 isSelected={isPopoverOpen}