Allow hidl_vec to contain a null buffer.

Which is valid when its size is zero.

Bug: 34234675
Test: hidl_test
Change-Id: I9322c215a4cd5a10adc82713e23d5e6ad9b0420d
diff --git a/transport/include/hidl/HidlBinderSupport.h b/transport/include/hidl/HidlBinderSupport.h
index d0ad3fb..120e818 100644
--- a/transport/include/hidl/HidlBinderSupport.h
+++ b/transport/include/hidl/HidlBinderSupport.h
@@ -96,7 +96,7 @@
         size_t parentOffset,
         size_t *handle) {
     const void *out;
-    return parcel.readEmbeddedBuffer(
+    return parcel.readNullableEmbeddedBuffer(
             handle,
             parentHandle,
             parentOffset + hidl_vec<T>::kOffsetOfBuffer,