Add event ping telemetry for the Baidu top site click

app/metrics.yaml

@@ -3886,6 +3886,19 @@ top_sites:
     notification_emails:
       - android-probes@mozilla.com
     expires: "2022-02-01"
+  open_baidu_search_attribution:
+    type: event
+    description: |
+      A user opened the baidu top site
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/19490
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/20705
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - android-probes@mozilla.com
+    expires: "2022-02-01"
   open_frecency:
     type: event
     description: |

app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt

@@ -129,6 +129,7 @@ sealed class Event {
     object NotificationMediaPause : Event()
     object TopSiteOpenDefault : Event()
     object TopSiteOpenGoogle : Event()
+    object TopSiteOpenBaidu : Event()
     object TopSiteOpenFrecent : Event()
     object TopSiteOpenPinned : Event()
     object TopSiteOpenInNewTab : Event()

app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt

@@ -544,6 +544,9 @@ private val Event.wrapper: EventWrapper<*>?
         is Event.TopSiteOpenGoogle -> EventWrapper<NoExtraKeys>(
             { TopSites.openGoogleSearchAttribution.record(it) }
         )
+        is Event.TopSiteOpenBaidu -> EventWrapper<NoExtraKeys>(
+            { TopSites.openBaiduSearchAttribution.record(it) }
+        )
         is Event.TopSiteOpenFrecent -> EventWrapper<NoExtraKeys>(
             { TopSites.openFrecency.record(it) }
         )

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/SessionControlController.kt

@@ -372,6 +372,10 @@ class DefaultSessionControlController(
             metrics.track(Event.TopSiteOpenGoogle)
         }
 
+        if (url == SupportUtils.BAIDU_URL) {
+            metrics.track(Event.TopSiteOpenBaidu)
+        }
+
         if (url == SupportUtils.POCKET_TRENDING_URL) {
             metrics.track(Event.PocketTopSiteClicked)
         }