Prevent chromatic build error on SearchBar

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

plugins/search/src/components/SearchBar/SearchBar.test.tsx

@@ -37,10 +37,10 @@ describe('SearchBar', () => {
   };
 
   const query = jest.fn().mockResolvedValue({});
-  const getString = jest.fn().mockReturnValue('Mock title');
+  const getOptionalString = jest.fn().mockReturnValue('Mock title');
 
   const apiRegistry = ApiRegistry.from([
-    [configApiRef, { getString }],
+    [configApiRef, { getOptionalString }],
     [searchApiRef, { query }],
   ]);
 

plugins/search/src/components/SearchBar/SearchBar.tsx

@@ -55,7 +55,8 @@ export const SearchBarBase = ({
   }, [onChange]);
 
   const placeholder =
-    overridePlaceholder ?? `Search in ${configApi.getString('app.title')}`;
+    overridePlaceholder ??
+    `Search in ${configApi.getOptionalString('app.title') || 'Backstage'}`;
 
   return (
     <InputBase