Autorest Client Runtime for Java 1.6.11

Do not use this version if you are running on Java 7 as OkHttp removed Java 7 support since 3.12. 1.6.12 release reverts the OkHttp version back to 3.12.2, which supports Java 7.

• Update OkHttp to 3.14.2 (fixes Azure/azure-sdk-for-java#3939)