Update s2 sample protoc usage for sdkhelpers update.

(TODO: update submodule after merge)

samples/s2_sample_mm/AMBuilder

@@ -9,29 +9,20 @@ import os
 for sdk_target in MMSPlugin.sdk_targets:
   sdk = sdk_target.sdk
   cxx = sdk_target.cxx
-  protoc = sdk_target.protoc
 
   binary = MMSPlugin.HL2Library(builder, cxx, MMSPlugin.plugin_name, sdk)
 
   binary.sources += [
-    'sample_mm.cpp'
+    'sample_mm.cpp',
   ]
 
   binary.sources += [
     os.path.join(sdk['path'], 'tier1', 'convar.cpp'),
     os.path.join(sdk['path'], 'public', 'tier0', 'memoverride.cpp')
   ]
-
-  proto_files = [
+  binary.custom = [builder.tools.Protoc(protoc = sdk_target.protoc, sources = [
     os.path.join(sdk['path'], 'common', 'network_connection.proto'),
-  ]
-
-  protoc.includes = [
-    os.path.join(sdk['path'], 'thirdparty', 'protobuf-3.21.8', 'src'),
-    os.path.join(sdk['path'], 'common'),
-  ]
-
-  binary.custom = [builder.tools.Protoc(sources = proto_files, protoc = protoc)]
+  ])]
 
   nodes = builder.Add(binary)
   MMSPlugin.binaries += [nodes]