Reword ambiguous documentation in Parcel

- original documentation for Parcel.unmarshall could be understood
  both ways: Parcel written with bytes of data, data written with
  bytes of Parcel

Test: Not applicable
Signed-off-by: danielzhang130 <danielzhang130@gmail.com>
Change-Id: I9afd3ae66ca03f391b272ac0524593395ffe53fa

core/java/android/os/Parcel.java

@@ -767,7 +767,7 @@ public final class Parcel {
     }
 
     /**
-     * Set the bytes in data to be the raw bytes of this Parcel.
+     * Fills the raw bytes of this Parcel with the supplied data.
      */
     public final void unmarshall(@NonNull byte[] data, int offset, int length) {
         nativeUnmarshall(mNativePtr, data, offset, length);