Change the conditions of layer as translucent

Only the  mSidebandStream  and mActiveBuffer are both null,the layer
is consider as translucent.Or else ,it will cause Composition::sideband
layer can not call into clear ClientTarget when SurfaceFlinger
doComposeSurfaces

Issue: 234427
Test: Live Channel
Change-Id: I19aeb7ac838baefe4b9b9417f87dd8a7d9b131b0
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
old mode 100644
new mode 100755
index d13b6db..0de5abc
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1271,9 +1271,9 @@
 
 bool Layer::isOpaque(const Layer::State& s) const
 {
-    // if we don't have a buffer yet, we're translucent regardless of the
+    // if we don't have a buffer or sidebandStream yet, we're translucent regardless of the
     // layer's opaque flag.
-    if (mActiveBuffer == 0) {
+    if ((mSidebandStream == nullptr) && (mActiveBuffer == nullptr)) {
         return false;
     }