[memory-usage] Propagate experiments through memory-usage test to client/server (#33206)

Will be used to evaluate experiment effects on memory usage once they're
toggled on.

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test/core/memory_usage/memory_usage_test.cc

@@ -36,6 +36,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/config/config_vars.h"
 #include "src/core/lib/gprpp/host_port.h"
 #include "test/core/util/port.h"
 #include "test/core/util/subprocess.h"
@@ -82,7 +83,9 @@ int RunCallBenchmark(char* root, std::vector<std::string> server_scenario_flags,
   std::vector<std::string> server_flags = {
       absl::StrCat(root, "/memory_usage_server",
                    gpr_subprocess_binary_extension()),
-      "--bind", grpc_core::JoinHostPort("::", port)};
+      "--grpc_experiments",
+      std::string(grpc_core::ConfigVars::Get().Experiments()), "--bind",
+      grpc_core::JoinHostPort("::", port)};
   // Add scenario-specific server flags to the end of the server_flags
   absl::c_move(server_scenario_flags, std::back_inserter(server_flags));
   Subprocess svr(server_flags);
@@ -91,7 +94,10 @@ int RunCallBenchmark(char* root, std::vector<std::string> server_scenario_flags,
   std::vector<std::string> client_flags = {
       absl::StrCat(root, "/memory_usage_client",
                    gpr_subprocess_binary_extension()),
-      "--target", grpc_core::JoinHostPort("127.0.0.1", port),
+      "--target",
+      grpc_core::JoinHostPort("127.0.0.1", port),
+      "--grpc_experiments",
+      std::string(grpc_core::ConfigVars::Get().Experiments()),
       absl::StrCat("--warmup=", 10000),
       absl::StrCat("--benchmark=", absl::GetFlag(FLAGS_size))};
   // Add scenario-specific client flags to the end of the client_flags