Fix core_untyped_structs sanity test

include/grpc/impl/codegen/compression_types.h

@@ -146,7 +146,7 @@ typedef struct grpc_compression_options {
    * default_algorithm. This option corresponds to the channel
    * argument key behind \a GRPC_STREAM_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM.
    */
-  struct {
+  struct grpc_stream_compression_options_default_algorithm {
     int is_set;
     grpc_stream_compression_algorithm algorithm;
   } default_stream_compression_algorithm;

include/grpc/impl/codegen/grpc_types.h

@@ -505,7 +505,7 @@ typedef struct grpc_op {
         uint8_t is_set;
         grpc_compression_level level;
       } maybe_compression_level;
-      struct {
+      struct grpc_op_send_initial_metadata_maybe_stream_compression_level {
         uint8_t is_set;
         grpc_stream_compression_level level;
       } maybe_stream_compression_level;