Added change logs

Author: joviegas

.changes/next-release/feature-AWSSDKforJavav2-9f69c81.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Fixed SigV4a signing to respect pre-existing Host headers to be consistent with existing SigV4 signing behavior."
+}