title: Android Firebase Analytics: predefined and custom parameters not working as expected
body: <p>I have a native Android project that uses Google Analytics for Firebase for its event reporting. I have a couple events that share the same parameters, but some of these count towards the custom parameter limit while others don't. The events I am using are suggested common events and are using mostly suggested parameters with one or two custom parameters. I have a few questions regarding the way events &amp; parameters are showing up on the Firebase console, using the examples below (you can assume the values provided are the correct datatypes).</p>
  
  <p>BEGIN_CHECKOUT</p>
  
  <pre><code>Bundle bundle = new Bundle();
  bundle.putString(FirebaseAnalytics.Param.ITEM_ID, itemId);
  bundle.putString(FirebaseAnalytics.Param.ORIGIN, itemOrigin);
  bundle.putString(FirebaseAnalytics.Param.DESTINATION, itemDestination);
  bundle.putString(FirebaseAnalytics.Param.START_DATE, itemStartDate);
  bundle.putString(FirebaseAnalytics.Param.END_DATE, itemEndDate);
  bundle.putLong(FirebaseAnalytics.Param.NUMBER_OF_PASSENGERS, itemNumberOfPassengers);
  bundle.putString(FirebaseAnalytics.Param.TRAVEL_CLASS, itemTravelClass);
  bundle.putString(FirebaseAnalytics.Param.CURRENCY, itemCurrency);
  bundle.putDouble(FirebaseAnalytics.Param.VALUE, itemValue);
  bundle.putString("travel_type", itemTravelType);
  mFirebaseAnalytics.logEvent(FirebaseAnalytics.Event.BEGIN_CHECKOUT, bundle);
  </code></pre>
  
  <p>In Firebase Analytics, on the events tab, this event shows up as follows:
  <a href="https://i.stack.imgur.com/MOow1.png" rel="noreferrer"><img src="https://i.stack.imgur.com/MOow1.png" alt="begin_checkout console"></a></p>
  
  <p>Another example:
  ECOMMERCE_PURCHASE</p>
  
  <pre><code>Bundle bundle = new Bundle();
  bundle.putString(FirebaseAnalytics.Param.ITEM_ID, itemId);
  bundle.putString(FirebaseAnalytics.Param.ORIGIN, itemOrigin);
  bundle.putString(FirebaseAnalytics.Param.DESTINATION, itemDestination);
  bundle.putString(FirebaseAnalytics.Param.START_DATE, itemStartDate);
  bundle.putString(FirebaseAnalytics.Param.END_DATE, itemEndDate);
  bundle.putLong(FirebaseAnalytics.Param.NUMBER_OF_PASSENGERS, itemNumberOfPassengers);
  bundle.putString(FirebaseAnalytics.Param.TRAVEL_CLASS, itemTravelClass);
  bundle.putString(FirebaseAnalytics.Param.CURRENCY, itemCurrency);
  bundle.putDouble(FirebaseAnalytics.Param.VALUE, itemValue);
  bundle.putString("travel_type", itemTravelType);
  mFirebaseAnalytics.logEvent(FirebaseAnalytics.Event.ECOMMERCE_PURCHASE, bundle);
  </code></pre>
  
  <p>Firebase console:</p>
  
  <p><a href="https://i.stack.imgur.com/qduVl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/qduVl.png" alt="ecommerce_purchase console"></a></p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>Why are some parameters "auto-added" to parameter reporting of begin_checkout on the Firebase Console, while others aren't? e.g. destination &amp; start_date vs. item_id &amp; currency</li>
  <li>Why don't these "auto-added" parameters show up on my dashboard? Only item_id is shown here.</li>
  <li>Why isn't a single parameter "auto-added" to the reporting of ecommerce_purchase? The parameters don't even show up on the list on the left, I need to type in the name of the parameters myself</li>
  <li>Are custom parameters shared between different events? For example I have the custom parameter "travel_type". To get this parameter to show on both events, I need to add this parameter to both events manually, thus this parameter counts twice towards the global limit of 10 text parameters?</li>
  <li>Am I just completely wrong in assuming that using the predefined parameters should not count towards the custom parameter limit? For example, "item_id" is a predefined parameter, yet it does count towards the global quota, is this intended behaviour?</li>
  </ol>
  
  <p>(Might be related, but my ecommerce_purchase event is marked as a conversion event automatically, and I cannot change this, while I have set begin_checkout as a conversion event manually).</p>
  
  <p>For the record, the data of these events &amp; parameters does show up nicely in the Stream -and DebugViews.</p>