Revert "Modified userstat where it passes in the trip_key as an input…

… instead of hardcoding analysis/confirmed_trip"

This reverts commit c77c5c5.

Reverting because this broke the tests.
#1006 (comment)

This is because the composite trips include both actual trips and untracked time.
#1006 (comment)

We don't want to store untracked time in the user stats or show it to users, so
we can't push this to a real production system, where people check the admin
dashboard, just yet. The fix is simple, but will take @TeachMeTW some time to
figure out. So let's revert the change for now.

emission/analysis/result/user_stat.py

@@ -61,9 +61,9 @@ def get_and_store_user_stats(user_id: str, trip_key: str) -> None:
         end_ts_result = ts.get_first_value_for_field(trip_key, "data.end_ts", pymongo.DESCENDING)
         end_ts = None if end_ts_result == -1 else end_ts_result
 
-        total_trips = ts.find_entries_count(key_list=[trip_key])
+        total_trips = ts.find_entries_count(key_list=["analysis/confirmed_trip"])
         labeled_trips = ts.find_entries_count(
-            key_list=[trip_key],
+            key_list=["analysis/confirmed_trip"],
             extra_query_list=[{'data.user_input': {'$ne': {}}}]
         )