Hi,
Each Android release documentation indicates the recommended build environment (mentioning version compatibility). Regarding the differences between Ubuntu 12.04 and 14.04, they are minimal; anyway, you could verify the specific requirements on the following link:
Establishing a Build Environment | Android Open Source Project
Hope this will be useful for you.
Best regards!
/Carlos
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------