Add jitter changelog entry.

Author: millems

.changes/next-release/feature-AWSSDKforJavav2-d28e3ad.json

@@ -0,0 +1,6 @@
+{
+    "type": "feature",
+    "category": "AWS SDK for Java v2",
+    "contributor": "",
+    "description": "Jitter credential provider cache refresh times."
+}