Snap to running task if it's offscreen when back is invoked

- If the user has scrolled the running task offscreen, then
  snap back to the task if back is invoked.

Bug: 233952141
Test: Swipe to overview, scroll away from the current task
      and then go back
Change-Id: Icc5040d4b38c97e0329f937e24bd517a71a32f13

quickstep/src/com/android/launcher3/uioverrides/states/OverviewState.java

@@ -131,9 +131,14 @@ public class OverviewState extends LauncherState {
 
     @Override
     public void onBackPressed(Launcher launcher) {
-        TaskView taskView = launcher.<RecentsView>getOverviewPanel().getRunningTaskView();
+        RecentsView recentsView = launcher.getOverviewPanel();
+        TaskView taskView = recentsView.getRunningTaskView();
         if (taskView != null) {
-            taskView.launchTasks();
+            if (recentsView.isTaskViewFullyVisible(taskView)) {
+                taskView.launchTasks();
+            } else {
+                recentsView.snapToPage(recentsView.indexOfChild(taskView));
+            }
         } else {
             super.onBackPressed(launcher);
         }