add env_vars nobuild

emby_beta/config.yaml

@@ -87,6 +87,7 @@ map:
   - ssl:rw
 name: Emby Beta
 options:
+  env_vars: []
   PGID: 0
   PUID: 0
   silent: true
@@ -106,6 +107,9 @@ privileged:
   - SYS_ADMIN
   - DAC_READ_SEARCH
 schema:
+  env_vars:
+    - name: match(^[A-Z0-9_]+$)
+      value: str?
   PGID: int
   PUID: int
   TZ: str?