Hi team, I'm proposing a change to how Beam Schemas are generated from Protobuf. Currently, all fields in Beam Schemas are treated as non-null, which doesn't align with Protobuf's concept of "presence" for optional fields. We need Beam Schemas to correctly handle nullable fields for optional Protobuf fields.
The full proposal is here: https://docs.google.com/document/d/1euOq_Uu4sycT-AiN6MQxJmsOgInyABiFSwW-U3kpwlk/edit?tab=t.0#heading=h.xzptrog8pyxf Thanks Minbo
