add analytics for clicks on drawer footer items

Also start segmenting menu_item clicks with useful data about the
click's context (like view mode, compose).

Bug: 11061485
Change-Id: I132117921bb45f81d2cd7d8433ab72543c9723fd
diff --git a/src/com/android/mail/compose/ComposeActivity.java b/src/com/android/mail/compose/ComposeActivity.java
index 2ad76d4..c0768ed 100644
--- a/src/com/android/mail/compose/ComposeActivity.java
+++ b/src/com/android/mail/compose/ComposeActivity.java
@@ -2058,7 +2058,8 @@
     public boolean onOptionsItemSelected(MenuItem item) {
         final int id = item.getItemId();
 
-        Analytics.getInstance().sendMenuItemEvent(Analytics.EVENT_CATEGORY_MENU_ITEM, id, null, 0);
+        Analytics.getInstance().sendMenuItemEvent(Analytics.EVENT_CATEGORY_MENU_ITEM, id,
+                "compose", 0);
 
         boolean handled = true;
         if (id == R.id.add_file_attachment) {