use MAX instead of SUM for calculating cumulative counts (#1264)

Author: bochocki

jetstream/whats-new-toast-notification-taskbar-tabs-release-v2.toml

@@ -73,26 +73,26 @@ data_source = "metrics"
 friendly_name = "Installed Web App"
 description = "Average Installed Web Apps per user (approx from install and uninstall events)"
 select_expression = """
-  COALESCE(SUM(CASE WHEN event_name = 'install' THEN cumulative_count END),0) -
-  COALESCE(SUM(CASE WHEN event_name = 'uninstall' THEN cumulative_count END),0)
+  COALESCE(MAX(CASE WHEN event_name = 'install' THEN cumulative_count END),0) -
+  COALESCE(MAX(CASE WHEN event_name = 'uninstall' THEN cumulative_count END),0)
 """
 data_source = "web_app_events"
 
 [metrics.unique_client_pins]
 friendly_name = "Pinned Web Apps"
 description = "Average Pinned Web Apps per user (approx from pin and unpin events)"
 select_expression = """
-  COALESCE(SUM(CASE WHEN event_name = 'pin' THEN cumulative_count END),0) -
-  COALESCE(SUM(CASE WHEN event_name = 'unpin' THEN cumulative_count END),0)
+  COALESCE(MAX(CASE WHEN event_name = 'pin' THEN cumulative_count END),0) -
+  COALESCE(MAX(CASE WHEN event_name = 'unpin' THEN cumulative_count END),0)
 """
 data_source = "web_app_events"
 
 [metrics.web_app_launches]
 friendly_name = "Web App Launches"
 description = "Average Web Apps Launches per user (approx from activate and move to taskbar events)"
 select_expression = """
-  COALESCE(SUM(CASE WHEN event_name = 'activate' THEN cumulative_count END),0) -
-  COALESCE(SUM(CASE WHEN event_name = 'install' THEN cumulative_count END),0)
+  COALESCE(MAX(CASE WHEN event_name = 'activate' THEN cumulative_count END),0) -
+  COALESCE(MAX(CASE WHEN event_name = 'install' THEN cumulative_count END),0)
 """
 data_source = "web_app_events"