Make LaunchContext courier-serializable
Make LaunchContext courier-serializable

Courier-serializability was broken due to the introduction of program stopper within LaunchContext.

PiperOrigin-RevId: 390379350
Change-Id: I9aa6c3e0f2b6600b11f4bf90da4067544db37175

deepmind/launchpad,deepmind/launchpad,deepmind/launchpad,deepmind/launchpad