Adding a new tracks event for when a checklist is inserted. (#624)

Author: roundhill

Simplenote/src/main/java/com/automattic/simplenote/NoteEditorFragment.java

@@ -476,6 +476,12 @@ public boolean onOptionsItemSelected(MenuItem item) {
 
     private void insertChecklist() {
         mContentEditText.insertChecklist();
+
+        AnalyticsTracker.track(
+                AnalyticsTracker.Stat.EDITOR_CHECKLIST_INSERTED,
+                AnalyticsTracker.CATEGORY_NOTE,
+                "toolbar_button"
+        );
     }
 
     private void deleteNote() {

Simplenote/src/main/java/com/automattic/simplenote/analytics/AnalyticsTracker.java

@@ -88,6 +88,7 @@ public enum Stat {
         EDITOR_NOTE_DELETED,
         EDITOR_NOTE_RESTORED,
         EDITOR_ACTIVITIES_ACCESSED,
+        EDITOR_CHECKLIST_INSERTED,
         EDITOR_COLLABORATORS_ACCESSED,
         EDITOR_VERSIONS_ACCESSED,
         EDITOR_NOTE_PUBLISHED,