Resetting taskView alpha to proper value onAnimationEnd

Bug: 135114549
Change-Id: I4effc4c9d8e6c03e41c8f06c441477076ce7a622
diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java
index 90e123e..f66e401 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java
@@ -892,7 +892,7 @@
         mRunningTaskTileHidden = isHidden;
         TaskView runningTask = getRunningTaskView();
         if (runningTask != null) {
-            runningTask.setAlpha(isHidden ? 0 : mContentAlpha);
+            runningTask.setStableAlpha(isHidden ? 0 : mContentAlpha);
         }
     }
 
@@ -1294,7 +1294,7 @@
         for (int i = getTaskViewCount() - 1; i >= 0; i--) {
             TaskView child = getTaskViewAt(i);
             if (!mRunningTaskTileHidden || child.getTask().key.id != mRunningTaskId) {
-                getChildAt(i).setAlpha(alpha);
+                child.setStableAlpha(alpha);
             }
         }
         mClearAllButton.setContentAlpha(mContentAlpha);
diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
index e0a4bca..354241b 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
@@ -163,6 +163,7 @@
     private ObjectAnimator mIconAndDimAnimator;
     private float mIconScaleAnimStartProgress = 0;
     private float mFocusTransitionProgress = 1;
+    private float mStableAlpha = 1;
 
     private boolean mShowScreenshot;
 
@@ -469,7 +470,7 @@
         setTranslationX(0f);
         setTranslationY(0f);
         setTranslationZ(0);
-        setAlpha(1f);
+        setAlpha(mStableAlpha);
         setIconScaleAndDim(1);
     }
 
@@ -478,6 +479,11 @@
         setFullscreenProgress(0);
     }
 
+    public void setStableAlpha(float parentAlpha) {
+        mStableAlpha = parentAlpha;
+        setAlpha(mStableAlpha);
+    }
+
     @Override
     public void onRecycle() {
         resetViewTransforms();