Make SurfaceControl Transaction parcelable 2/2

Allow clients to send SurfaceControl Transactions across processes to
enable more advanced synchronization use cases.

Bug: 132205507
Test: atest SurfaceFlinger_test
Change-Id: I20a33cafc0960e73f9a2c3d740f81319e02b68ff
diff --git a/libs/gui/SurfaceControl.cpp b/libs/gui/SurfaceControl.cpp
index 55488da..d87a447 100644
--- a/libs/gui/SurfaceControl.cpp
+++ b/libs/gui/SurfaceControl.cpp
@@ -186,8 +186,7 @@
     parcel->writeStrongBinder(IGraphicBufferProducer::asBinder(mGraphicBufferProducer));
 }
 
-sp<SurfaceControl> SurfaceControl::readFromParcel(Parcel* parcel)
-{
+sp<SurfaceControl> SurfaceControl::readFromParcel(const Parcel* parcel) {
     sp<IBinder> client = parcel->readStrongBinder();
     sp<IBinder> handle = parcel->readStrongBinder();
     if (client == nullptr || handle == nullptr)