Add plumbing for sending stretch effect to SF

Bug: 179047472
Test: builds & boots, doesn't do anything yet
Change-Id: Ib8cccdde518f0591c2f2ee3416684442f37a1e06
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index fff3305..f053372 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -167,6 +167,9 @@
         SAFE_PARCEL(output.writeInt32, region.right);
         SAFE_PARCEL(output.writeInt32, region.bottom);
     }
+
+    SAFE_PARCEL(output.write, stretchEffect);
+
     return NO_ERROR;
 }
 
@@ -290,6 +293,9 @@
         SAFE_PARCEL(input.readInt32, &region.bottom);
         blurRegions.push_back(region);
     }
+
+    SAFE_PARCEL(input.read, stretchEffect);
+
     return NO_ERROR;
 }