Add CreatePresignedPostAsync to interface definitions (#3926)

* add CreatePresignedPost interface definitions

* add dev config

Author: GarrettBeatty

generator/.DevConfigs/d3558e54-ee23-4124-b05a-3a5be447970e.json

@@ -0,0 +1,11 @@
+{
+  "services": [
+    {
+      "serviceName": "S3",
+      "type": "patch",
+      "changeLogMessages": [
+        "Add CreatePresignedPost to interface"
+      ]
+    }
+  ]
+}

sdk/src/Services/S3/Custom/IAmazonS3.Extensions.cs

@@ -74,5 +74,27 @@ public partial interface IAmazonS3 : IDisposable, Amazon.Runtime.SharedInterface
         Task<string> GetPreSignedURLAsync(GetPreSignedUrlRequest request);
 
         #endregion
+
+        #region CreatePresignedPost
+
+        /// <summary>
+        /// Create a presigned POST request that can be used to upload a file directly to S3 from a web browser.
+        /// </summary>
+        /// <param name="request">The CreatePresignedPostRequest that defines the parameters of the operation.</param>
+        /// <returns>A CreatePresignedPostResponse containing the URL and form fields for the POST request.</returns>
+        /// <exception cref="T:System.ArgumentException" />
+        /// <exception cref="T:System.ArgumentNullException" />
+        CreatePresignedPostResponse CreatePresignedPost(CreatePresignedPostRequest request);
+
+        /// <summary>
+        /// Asynchronously create a presigned POST request that can be used to upload a file directly to S3 from a web browser.
+        /// </summary>
+        /// <param name="request">The CreatePresignedPostRequest that defines the parameters of the operation.</param>
+        /// <returns>A CreatePresignedPostResponse containing the URL and form fields for the POST request.</returns>
+        /// <exception cref="T:System.ArgumentException" />
+        /// <exception cref="T:System.ArgumentNullException" />
+        Task<CreatePresignedPostResponse> CreatePresignedPostAsync(CreatePresignedPostRequest request);
+
+        #endregion
     }
 }