Changes still in progress on the proto field mapping.

…the ServerServiceDefinition.

…rverServiceDefinition constructed from that of the v1 service but with the service and method names and proto descriptors modified.

…rverServiceDefinition constructed from that of the v1 service but with the service and method names and proto descriptors modified.

Issue grpc#6724.

Squashed commit of the following:

commit f1f2da7
Author: Kannan J <[email protected]>
Date:   Tue May 28 10:24:32 2024 +0000

    Some nitty changes.

commit 34f81e5
Author: Kannan J <[email protected]>
Date:   Tue May 28 10:09:49 2024 +0000

    Create ProtoReflectionService for the v1alpha proto by producing a ServerServiceDefinition constructed from that of the v1 service but with the service and method names and proto descriptors modified.

commit e99a8da
Author: Kannan J <[email protected]>
Date:   Fri May 24 11:20:28 2024 +0000

    Create V1 alpha service wrapping underlying V1 service, by modifying the ServerServiceDefinition.

commit b2bb9e1
Author: Kannan J <[email protected]>
Date:   Fri May 24 07:14:42 2024 +0000

    Changes to allow unit testing.

commit a002bc2
Author: Kannan J <[email protected]>
Date:   Wed May 22 11:53:27 2024 +0000

    Issue grpc#6724 to create a V1 reflection service.
    Changes still in progress on the proto field mapping.

…ectionservice

# Conflicts:
#	services/src/main/java/io/grpc/protobuf/services/ProtoReflectionService.java

/grpc-java/services/src/main/java/io/grpc/protobuf/services/ProtoReflectionService.java:76: warning: [unchecked] unchecked method invocation: method addMethod in class Builder is applied to given types
        .addMethod(methodDescriptorV1Alpha, createServerCallHandler(serverServiceDefinitionV1))
                  ^
  required: MethodDescriptor,ServerCallHandler
  found: MethodDescriptor,ServerCallHandler
  where ReqT,RespT are type-variables:
    ReqT extends Object declared in method addMethod(MethodDescriptor,ServerCallHandler)
    RespT extends Object declared in method addMethod(MethodDescriptor,ServerCallHandler)

…dler.