Fix minor generator issues (#465)

Author: nateprewitt

codegen/aws/core/src/main/java/software/amazon/smithy/python/aws/codegen/AwsUserAgentIntegration.java

@@ -28,7 +28,7 @@ def aws_user_agent_plugin(config: $1T):
                         ua_suffix=config.user_agent_extra,
                         ua_app_id=config.sdk_ua_app_id,
                         sdk_version=$3T,
-                        service_id='$4L'
+                        service_id=$4S,
                     )
                 )
             """;

codegen/core/src/main/java/software/amazon/smithy/python/codegen/HttpAuthGenerator.java

@@ -149,7 +149,7 @@ private void writeAuthOptions(PythonWriter writer, List<AuthScheme> authSchemes)
         writer.putContext("authOptionInitializers", authOptionInitializers);
         writer.write("""
                 ${#authOptionInitializers}
-                if ((option := ${value:T}(auth_parameters)) is not None):
+                if (option := ${value:T}(auth_parameters)) is not None:
                     auth_options.append(option)
 
                 ${/authOptionInitializers}

codegen/core/src/main/java/software/amazon/smithy/python/codegen/generators/InitGenerator.java

@@ -43,6 +43,6 @@ public void run() {
         context.writerDelegator()
                 .useFileWriter(
                         "%s/__init__.py".formatted(context.settings().moduleName()),
-                        w -> w.write("__version__: str = '$L'", context.settings().moduleVersion()));
+                        w -> w.write("__version__: str = $S", context.settings().moduleVersion()));
     }
 }

codegen/core/src/main/java/software/amazon/smithy/python/codegen/integrations/RestJsonProtocolGenerator.java

@@ -134,7 +134,7 @@ protected void serializeDocumentBody(
         writer.pushState();
 
         if (documentBindings.isEmpty()) {
-            var body = shouldWriteDefaultBody(context, operation) ? "b'{}'" : "b''";
+            var body = shouldWriteDefaultBody(context, operation) ? "b\"{}\"" : "b\"\"";
             writer.write("""
                     content_length = 0
                     body = SeekableAsyncBytesReader($L)
@@ -147,7 +147,7 @@ protected void serializeDocumentBody(
                     content = codec.serialize(input)
                     ${?writeDefaultBody}
                     if not content:
-                        content = b'{}'
+                        content = b\"{}\"
                     ${/writeDefaultBody}
                     content_length = len(content)
                     body = SeekableAsyncBytesReader(content)
@@ -255,7 +255,7 @@ protected void serializePayloadBody(
             writer.write("""
                     else:
                         content_length = 2
-                        body = SeekableAsyncBytesReader(b'{}')
+                        body = SeekableAsyncBytesReader(b\"{}\")
                     """);
         }
     }