add changelog entry

Author: Nicholas DeJaco

.changes/next-release/feature-AWSSDKforJavav2-fdb476d.json

@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "ndejaco2", 
+    "type": "feature", 
+    "description": "This feature adds client and request overrides of execution attributes prior to request invocation."
+}