Revert^2: Expand minimized split stack on relaunch-attempt

If a relaunch-attempt is made on the app in a minimized
primary-split, just expand it. This way its clear to the user
what happened and is much closer to their intent. Previously,
this was just opening recents; however, that doesn't make sense
for pixel launcher (which remains in minimized-dock even with
recents active) because the actual launched-app is still
not-focusable and partially obscured.

Also, modified the restart-attempt logic to directly check if
divider is minimized rather than homeTaskVisible since that is
semantically what matters.

Bug: 152772854
Test: Open an app into split-screen primary with launcher in
      secondary. Then launch the same app from launcher.
Change-Id: I45b80ee8b8596a2a4e2e9cd91624398beaed20bd

packages/SystemUI/src/com/android/systemui/recents/OverviewProxyRecentsImpl.java

@@ -71,12 +71,13 @@ public class OverviewProxyRecentsImpl implements RecentsImplementation {
         public void onActivityRestartAttempt(ActivityManager.RunningTaskInfo task,
                 boolean homeTaskVisible, boolean clearedTask) {
             if (task.configuration.windowConfiguration.getWindowingMode()
-                    != WINDOWING_MODE_SPLIT_SCREEN_PRIMARY) {
+                    != WINDOWING_MODE_SPLIT_SCREEN_PRIMARY || !mDividerOptional.isPresent()) {
                 return;
             }
 
-            if (homeTaskVisible) {
-                showRecentApps(false /* triggeredFromAltTab */);
+            final Divider divider = mDividerOptional.get();
+            if (divider.isMinimized()) {
+                divider.onUndockingTask();
             }
         }
     };