[BEAM-13015] Disable retries for fnapi grpc channels which otherwise …

…defaults on. (apache#17243)

* [BEAM-13015] Disable retries for grpc channels which otherwise default to true.

Since the channel is to the local runner process, retries are not expected to
help. This simplifies the grpc stream stack to not involve a RetryStream object.

* fixup comment

* Update sdks/java/fn-execution/src/main/java/org/apache/beam/sdk/fn/channel/ManagedChannelFactory.java

* Update sdks/java/fn-execution/src/main/java/org/apache/beam/sdk/fn/channel/ManagedChannelFactory.java

Co-authored-by: Lukasz Cwik <lcwik@google.com>

sdks/java/fn-execution/src/main/java/org/apache/beam/sdk/fn/channel/ManagedChannelFactory.java

@@ -89,6 +89,11 @@ public ManagedChannel forDescriptor(ApiServiceDescriptor apiServiceDescriptor) {
             // Set the message size to max value here. The actual size is governed by the
             // buffer size in the layers above.
             .maxInboundMessageSize(Integer.MAX_VALUE)
+            // Disable automatic retries as it introduces complexity and we send long-lived
+            // rpcs which will exceed the per-rpc retry request buffer and not be retried
+            // anyway. See
+            // https://github.com/grpc/proposal/blob/master/A6-client-retries.md#when-retries-are-valid
+            .disableRetry()
             .intercept(interceptors);
     if (directExecutor) {
       channelBuilder = channelBuilder.directExecutor();