fix double slash in share link (#46757) (#46785)

(cherry picked from commit 18c1c6ca6a)

Co-authored-by: Santiago <santiagohernandez.1997@gmail.com>

public/app/features/alerting/unified/components/rules/RuleDetailsActionButtons.tsx

@@ -61,8 +61,10 @@ export const RuleDetailsActionButtons: FC<Props> = ({ rule, rulesSource }) => {
 
   const buildShareUrl = () => {
     if (isCloudRulesSource(rulesSource)) {
+      const { appUrl, appSubUrl } = config;
+      const baseUrl = appSubUrl !== '' ? `${appUrl}${appSubUrl}/` : config.appUrl;
       const ruleUrl = `${encodeURIComponent(rulesSource.name)}/${encodeURIComponent(rule.name)}`;
-      return `${config.appUrl}${config.appSubUrl}/alerting/${ruleUrl}/find`;
+      return `${baseUrl}alerting/${ruleUrl}/find`;
     }
 
     return window.location.href.split('?')[0];