Flip the default for experimental_stream_output.
Flip the default for experimental_stream_output.

PiperOrigin-RevId: 428050779
Change-Id: I069c6caa0cab90f7ac7a26cbc1b797e200efed24
GitOrigin-RevId: e1370fd08e5026a0ceaac2b7d62d4deaf6ce2253

deepmind/xmanager,deepmind/xmanager