make transparent pixels transparents again

apparently boolean logic in hard...

Change-Id: Ie70401fe12e0fa00b0b8c7cc475c1438cdbbf531
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 1a25abe..c2b52f6 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -584,10 +584,10 @@
         case HAL_PIXEL_FORMAT_BGRA_8888:
         case HAL_PIXEL_FORMAT_RGBA_5551:
         case HAL_PIXEL_FORMAT_RGBA_4444:
-            return true;
+            return false;
     }
     // in all other case, we have no blending (also for unknown formats)
-    return false;
+    return true;
 }
 
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