Don't send split info callback before activity is created

Sending a split info callback before activity created would
give developer a reference to a not fully initalized class.
It is possible that an attemp to apply actions to such an
activity in the split callback would lead to unexpected
issues for developers. E.g. one might assuming that the
UI for an activity would've been constructed at this point
and try to update it to fit the split or collapsed state
requirements.

Bug: 228770009
Test: atest CtsWindowManagerJetpackTestCases:ActivityEmbeddingLifecycleTests
Change-Id: I3a19a028ad6da9a6d534a97d315bce5f95b191af

libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/SplitController.java

@@ -757,22 +757,14 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         return null;
     }
 
-    private void updateCallbackIfNecessary() {
-        updateCallbackIfNecessary(true /* deferCallbackUntilAllActivitiesCreated */);
-    }
-
     /**
      * Notifies listeners about changes to split states if necessary.
-     *
-     * @param deferCallbackUntilAllActivitiesCreated boolean to indicate whether the split info
-     *                                               callback should be deferred until all the
-     *                                               organized activities have been created.
      */
-    private void updateCallbackIfNecessary(boolean deferCallbackUntilAllActivitiesCreated) {
+    private void updateCallbackIfNecessary() {
         if (mEmbeddingCallback == null) {
             return;
         }
-        if (deferCallbackUntilAllActivitiesCreated && !allActivitiesCreated()) {
+        if (!allActivitiesCreated()) {
             return;
         }
         List<SplitInfo> currentSplitStates = getActiveSplitStates();
@@ -828,9 +820,7 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
         for (int i = mTaskContainers.size() - 1; i >= 0; i--) {
             final List<TaskFragmentContainer> containers = mTaskContainers.valueAt(i).mContainers;
             for (TaskFragmentContainer container : containers) {
-                if (container.getInfo() == null
-                        || container.getInfo().getActivities().size()
-                        != container.collectActivities().size()) {
+                if (!container.taskInfoActivityCountMatchesCreated()) {
                     return false;
                 }
             }
@@ -1011,11 +1001,8 @@ public class SplitController implements JetpackTaskFragmentOrganizer.TaskFragmen
                             && container.getTaskFragmentToken().equals(initialTaskFragmentToken)) {
                         // The onTaskFragmentInfoChanged callback containing this activity has not
                         // reached the client yet, so add the activity to the pending appeared
-                        // activities and send a split info callback to the client before
-                        // {@link Activity#onCreate} is called.
+                        // activities.
                         container.addPendingAppearedActivity(activity);
-                        updateCallbackIfNecessary(
-                                false /* deferCallbackUntilAllActivitiesCreated */);
                         return;
                     }
                 }

libs/WindowManager/Jetpack/src/androidx/window/extensions/embedding/TaskFragmentContainer.java

@@ -119,6 +119,18 @@ class TaskFragmentContainer {
         return allActivities;
     }
 
+    /**
+     * Checks if the count of activities from the same process in task fragment info corresponds to
+     * the ones created and available on the client side.
+     */
+    boolean taskInfoActivityCountMatchesCreated() {
+        if (mInfo == null) {
+            return false;
+        }
+        return mPendingAppearedActivities.isEmpty()
+                && mInfo.getActivities().size() == collectActivities().size();
+    }
+
     ActivityStack toActivityStack() {
         return new ActivityStack(collectActivities(), isEmpty());
     }