[BEAM-14032] Create SchemaTransform external transform registrar

• Type: Sub-task
• Status: Open
• Priority: P2
• Resolution: Unresolved
• Component/s: sdk-java-core
• Assignee: Unassigned
• Reporter: Lara Schmidt
• Created: 02/Mar/22 21:48
• Updated: 04/Jun/22 23:24

Description

Create a SchemaTransform external transform registrar so that SchemaTransforms can be used cross language.

A similar one exists for SchemaIO:
sdks/java/extensions/schemaio-expansion-service/src/main/java/org/apache/beam/sdk/extensions/schemaio/expansion/ExternalSchemaIOTransformRegistrar.java