Description of problem:
Setting HeatAuthEncryptionKey in an environment file isn't setting the value in deployments but it works if we override it with :
  controllerExtraConfig:
    heat::engine::auth_encryption_key: new_key


Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Try overriding the auth_encryption_key using HeatAuthEncryptionKey
2.
3.

Actual results:
Doesn't update the key

Expected results:
Should update the key

Additional info:
We can see both values in hiera data and since ExtraConfig overrides the default configuration, it works.