Add a 40 second sleep at the end of each Fireperf e2e test to ensure that events are sent before the app exits. (#5262)

This should fix the flaky TAP tests that expect traces to be sent.

Author: raymondlam

firebase-perf/e2e-app/src/androidTest/java/com/google/firebase/testing/fireperf/FirebasePerformanceFragmentScreenTracesTest.java

@@ -58,6 +58,7 @@ public void scrollAndCycleThroughAllFragments() throws InterruptedException {
 
     // End Activity screen trace by relaunching the activity to ensure the screen trace is sent.
     scenario.launch(FirebasePerfFragmentsActivity.class);
+    Thread.sleep(30 * 1000);
   }
 
   private void scrollRecyclerViewToEnd(int itemCount, int viewId) {

firebase-perf/e2e-app/src/androidTest/java/com/google/firebase/testing/fireperf/FirebasePerformanceScreenTracesTest.java

@@ -51,5 +51,6 @@ public void scrollRecyclerViewToEnd() {
     }
     // End Activity screen trace by switching to another Activity
     scenario.launch(FirebasePerfScreenTracesActivity.class);
+    Thread.sleep(30 * 1000);
   }
 }

firebase-perf/e2e-app/src/androidTest/java/com/google/firebase/testing/fireperf/FirebasePerformanceTest.java

@@ -60,5 +60,6 @@ public void waitForBothTracesAndNetworkRequestsBatch()
     for (Future<?> future : futureList) {
       future.get();
     }
+    Thread.sleep(30 * 1000);
   }
 }