Log visibility change for DialogCreatable in Settings.

Bug: 30681529
Test: adb logcat -b events | egrep "(sysui_|notification_)"
Test: make RunSettingsRoboTests
Change-Id: I51754d258ba1ddfae24323681f21cd02de4dbb4e

src/com/android/settings/TetherSettings.java

@@ -259,6 +259,14 @@ public class TetherSettings extends RestrictedSettingsFragment
         return null;
     }
 
+    @Override
+    public int getDialogMetricsCategory(int dialogId) {
+        if (dialogId == DIALOG_AP_SETTINGS) {
+            return MetricsEvent.DIALOG_AP_SETTINGS;
+        }
+        return 0;
+    }
+
     private class TetherChangeReceiver extends BroadcastReceiver {
         @Override
         public void onReceive(Context content, Intent intent) {