QueryContainerBuilderParcelizeTest

Proves the legacy QueryContainerBuilder keeps its Android Parcelable contract after the move to :compat.

The round trip is exercised with Robolectric because the mockable android.jar used by plain unit tests cannot perform stateful android.os.Parcel writes.

The @RawValue variable/extensions maps are written through Parcel.writeValue, which supports primitives, strings, maps, lists, and Parcelable/Serializable entries. Non-parcelable values (such as the PersistedQuery extension payload) are a documented legacy limitation and fail on write, exactly as in the historical artifact.