Revert "Only add divider when it need to show"

This reverts commit a0ee06083c.

Reason for revert: Cause cf devices cts tests failed

Bug: 158836294
Change-Id: I5b439cf1aaee51f0c6d2e7e7e8d73487ec851648

packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java

@@ -253,9 +253,7 @@ public class Divider extends SystemUI implements DividerView.DividerCallbacks,
             mSplitLayout.mSecondary = new Rect(mRotateSplitLayout.mSecondary);
             mRotateSplitLayout = null;
         }
-        if (isSplitActive()) {
-            update(newConfig);
-        }
+        update(newConfig);
     }
 
     Handler getHandler() {
@@ -330,6 +328,11 @@ public class Divider extends SystemUI implements DividerView.DividerCallbacks,
         mHandler.post(this::removeDivider);
     }
 
+    void onTasksReady() {
+        mHandler.post(() -> update(mDisplayController.getDisplayContext(
+                mContext.getDisplayId()).getResources().getConfiguration()));
+    }
+
     private void updateVisibility(final boolean visible) {
         if (DEBUG) Slog.d(TAG, "Updating visibility " + mVisible + "->" + visible);
         if (mVisible != visible) {
@@ -521,7 +524,7 @@ public class Divider extends SystemUI implements DividerView.DividerCallbacks,
 
     void ensureMinimizedSplit() {
         setHomeMinimized(true /* minimized */, mSplits.mSecondary.isResizable());
-        if (mView != null && !isDividerVisible()) {
+        if (!isDividerVisible()) {
             // Wasn't in split-mode yet, so enter now.
             if (DEBUG) {
                 Slog.d(TAG, " entering split mode with minimized=true");
@@ -532,7 +535,7 @@ public class Divider extends SystemUI implements DividerView.DividerCallbacks,
 
     void ensureNormalSplit() {
         setHomeMinimized(false /* minimized */, mHomeStackResizable);
-        if (mView != null && !isDividerVisible()) {
+        if (!isDividerVisible()) {
             // Wasn't in split-mode, so enter now.
             if (DEBUG) {
                 Slog.d(TAG, " enter split mode unminimized ");

packages/SystemUI/src/com/android/systemui/stackdivider/SplitScreenTaskOrganizer.java

@@ -113,6 +113,8 @@ class SplitScreenTaskOrganizer extends TaskOrganizer {
                 t.setColor(mSecondaryDim, new float[]{0f, 0f, 0f});
                 t.apply();
                 releaseTransaction(t);
+
+                mDivider.onTasksReady();
             }
         }
     }