ui: Link to public version of extension page

The old link was google-internal.

Change-Id: Ieb58cb9c1270dbf81cf7167b566f16fc0d4eccb1
diff --git a/ui/src/frontend/record_page.ts b/ui/src/frontend/record_page.ts
index 47c42e2..7fac1cb 100644
--- a/ui/src/frontend/record_page.ts
+++ b/ui/src/frontend/record_page.ts
@@ -769,7 +769,7 @@
 
 function RecordingNotes() {
   const docUrl = '//docs.perfetto.dev/#/build-instructions?id=get-the-code';
-  const extensionURL = `https://chrome.google.com/webstore/a/google.com/detail/
+  const extensionURL = `https://chrome.google.com/webstore/detail/
       perfetto-ui/lfmkphfpdbjijhpomgecfikhfohaoine`;
 
   const notes: m.Children = [];