Add tracking for where change starring comes from

Change starring is currently always shown at the dashboard and has
some usage but we cannot track from which view the user is starring
the change, hence add tracking for it to find dashboard usage of
change starring.

Change-Id: Ib830bc7427616a14d7a30314822661b617d0b924
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
index ea5339e..2086270 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-view/gr-change-list-view.ts
@@ -108,6 +108,8 @@
 
   private readonly restApiService = appContext.restApiService;
 
+  private reporting = appContext.reportingService;
+
   constructor() {
     super();
     this.addEventListener('next-page', () => this._handleNextPage());
@@ -272,6 +274,9 @@
   }
 
   _handleToggleStar(e: CustomEvent<ChangeStarToggleStarDetail>) {
+    if (e.detail.starred) {
+      this.reporting.reportInteraction('change-starred-from-change-list');
+    }
     this.restApiService.saveChangeStarred(
       e.detail.change._number,
       e.detail.starred
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
index bde7d77..e93b293 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
@@ -372,6 +372,9 @@
       e.detail.change._number,
       e.detail.starred
     );
+    if (e.detail.starred) {
+      this.reporting.reportInteraction('change-starred-from-dashboard');
+    }
     // When a change is updated the same change may appear elsewhere in the
     // dashboard (but is not the same object), so we must update other
     // occurrences of the same change.
diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
index c6d2ee0..580546a 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
@@ -2522,6 +2522,7 @@
 
   _handleToggleStar(e: CustomEvent<{change: ChangeInfo; starred: boolean}>) {
     if (e.detail.starred) {
+      this.reporting.reportInteraction('change-starred-from-change-view');
       this.lastStarredTimestamp = Date.now();
     } else {
       if (