Use edge conditions to process supportbot token

app/assets/javascripts/filtered_search/filtered_search_manager.js

@@ -649,10 +649,7 @@ export default class FilteredSearchManager {
           hasFilteredSearch = true;
           const canEdit = this.canEdit && this.canEdit(key, sanitizedValue);
           const { uppercaseTokenName, capitalizeTokenValue } = match;
-          const isSupportBot = keyParam === 'author_username' && value === 'support-bot';
-          const operator = isSupportBot
-            ? '='
-            : FilteredSearchVisualTokens.getOperatorToken(sanitizedValue);
+          const operator = FilteredSearchVisualTokens.getOperatorToken(sanitizedValue);
           const sanitizedToken = FilteredSearchVisualTokens.getValueToken(sanitizedValue);
           FilteredSearchVisualTokens.addFilterVisualToken(
             key,

app/assets/javascripts/filtered_search/issuable_filtered_search_token_keys.js

@@ -85,6 +85,11 @@ export const conditions = flattenDeep(
       tokenKey: 'assignee',
       value: __('Any'),
     },
+    {
+      url: 'author_username=support-bot',
+      tokenKey: 'author',
+      value: 'support-bot',
+    },
     {
       url: 'milestone_title=None',
       tokenKey: 'milestone',