rebase: bump google.golang.org/grpc from 1.69.4 to 1.70.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.69.4 to 1.70.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.69.4...v1.70.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/grpc/internal/envconfig/envconfig.go

@@ -49,7 +49,7 @@ var (
 	// XDSFallbackSupport is the env variable that controls whether support for
 	// xDS fallback is turned on. If this is unset or is false, only the first
 	// xDS server in the list of server configs will be used.
-	XDSFallbackSupport = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FALLBACK", false)
+	XDSFallbackSupport = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FALLBACK", true)
 	// NewPickFirstEnabled is set if the new pickfirst leaf policy is to be used
 	// instead of the exiting pickfirst implementation. This can be enabled by
 	// setting the environment variable "GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST"

vendor/google.golang.org/grpc/internal/envconfig/xds.go

@@ -53,4 +53,10 @@ var (
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
 	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+
+	// XDSDualstackEndpointsEnabled is true if gRPC should read the
+	// "additional addresses" in the xDS endpoint resource.
+	// TODO: https://github.com/grpc/grpc-go/issues/7866 - Control this using
+	// an env variable when all LB policies handle endpoints.
+	XDSDualstackEndpointsEnabled = false
 )

vendor/google.golang.org/grpc/internal/internal.go

@@ -31,6 +31,10 @@ import (
 var (
 	// HealthCheckFunc is used to provide client-side LB channel health checking
 	HealthCheckFunc HealthChecker
+	// RegisterClientHealthCheckListener is used to provide a listener for
+	// updates from the client-side health checking service. It returns a
+	// function that can be called to stop the health producer.
+	RegisterClientHealthCheckListener any // func(ctx context.Context, sc balancer.SubConn, serviceName string, listener func(balancer.SubConnState)) func()
 	// BalancerUnregister is exported by package balancer to unregister a balancer.
 	BalancerUnregister func(name string)
 	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by

vendor/google.golang.org/grpc/internal/transport/handler_server.go

@@ -498,5 +498,5 @@ func mapRecvMsgError(err error) error {
 	if strings.Contains(err.Error(), "body closed by handler") {
 		return status.Error(codes.Canceled, err.Error())
 	}
-	return connectionErrorf(true, err, err.Error())
+	return connectionErrorf(true, err, "%s", err.Error())
 }

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -564,7 +564,7 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
 		t.controlBuf.put(&earlyAbortStream{
-			httpStatus:     405,
+			httpStatus:     http.StatusMethodNotAllowed,
 			streamID:       streamID,
 			contentSubtype: s.contentSubtype,
 			status:         status.New(codes.Internal, errMsg),
@@ -585,7 +585,7 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 				stat = status.New(codes.PermissionDenied, err.Error())
 			}
 			t.controlBuf.put(&earlyAbortStream{
-				httpStatus:     200,
+				httpStatus:     http.StatusOK,
 				streamID:       s.id,
 				contentSubtype: s.contentSubtype,
 				status:         stat,