Update CHANGELOG.md (#1227)

Author: desokroshan

CHANGELOG.md

@@ -7,6 +7,9 @@
 - **AWS IoT**
   - AWS Android SDK for IoT now depends on the 1.2.2 version of the Paho Library org.eclipse.paho.client.mqttv3
 
+- Model updates for the following services
+  - Amazon Transcribe
+
 ## [Release 2.16.0](https://github.com/aws/aws-sdk-android/releases/tag/release_v2.16.0)
 
 ### New Features