Signed-off-by: Nxiaolong.ran <rxl@apache.org>

Fixes #5687 

### Motivation

When the user wants to add new keys for Env, adding fails if no prefix is added. 

Currently, add new keys for Env use the script of [apply-config-from-env.py](https://github.com/apache/pulsar/commits/master/docker/pulsar/scripts/apply-config-from-env.py), to ensure that the env set by the user can take effect, add the prefix(**PULSAR_PREFIX_**) for all keys.

### Modifications

- Add prefix for new keys from Env