Refresh Task overlay when thumbnail is refreshed

- TaplTestQuickStep.testOverviewActions is failing on cuttlefish large screens due to overview actions being disabled by NO_THUMBNAIL, which should be caused by thumbnail being loaded after overlay is enabled, a overlay refresh after thumbnails is loaded should fix the problem

Bug: 193125090
Test: manual
Change-Id: I3fa8093012c3d22adac49e5e0716576706a85dfa
diff --git a/quickstep/src/com/android/quickstep/views/TaskThumbnailView.java b/quickstep/src/com/android/quickstep/views/TaskThumbnailView.java
index 89e56ac..1ced86b 100644
--- a/quickstep/src/com/android/quickstep/views/TaskThumbnailView.java
+++ b/quickstep/src/com/android/quickstep/views/TaskThumbnailView.java
@@ -31,8 +31,6 @@
 import android.graphics.Insets;
 import android.graphics.Matrix;
 import android.graphics.Paint;
-import android.graphics.PorterDuff;
-import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.Shader;
@@ -165,6 +163,7 @@
             mBitmapShader = new BitmapShader(bm, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
             mPaint.setShader(mBitmapShader);
             updateThumbnailMatrix();
+            refreshOverlay();
         } else {
             mBitmapShader = null;
             mThumbnailData = null;