Remove reference to read/writeWeakBinder.

Unused.

Bug: 137785053
Test: build only
Change-Id: I47fdc40943b68afe9a6e26d218b4e6d651d42a1f
diff --git a/include/binder/auto_parcelable.h b/include/binder/auto_parcelable.h
index ef2d22f..357615c 100644
--- a/include/binder/auto_parcelable.h
+++ b/include/binder/auto_parcelable.h
@@ -116,7 +116,6 @@
 FN(String16,const String16&)\
 FN(String16,const std::unique_ptr<String16>&)\
 FN(StrongBinder,const sp<IBinder>&)\
-FN(WeakBinder,const wp<IBinder>&)\
 
   template <typename F>
   static status_t writeAnyToParcel(Parcel* parcel, const F& value) {