The documentation for TemporaryBuffer::length says:
"The length is only accurate after {@link #close()} has been invoked".
However, we need to have the stream open while accessing the length.
This prevents patches on large files to be applied correctly, as the
result get trimmed.
Bug: Google b/309500446
Change-Id: Ic1540f6d0044088f3b46f1fad5f6a28ec254b711