Fix ES6-to-ES5 translation of language mapping
Fix ES6-to-ES5 translation of language mapping

Tests on IE and Tizen were broken in 4d41b7b9
when the language mapping was added to the test
environment without Babel config to translate it.

This went unnoticed because of a lab failure.

Change-Id: Ib6517d30c82376e4f828d2ceb7e63de1cb7bcc95

tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player