Have proper default for webserver.expose_config in Helm Chart (#13596)

webserver.expose_config should have consistent default value with
the normal Airflow default settings (False).

This helps encourage safer setting up in Helm context, also avoid
accidental exposure of config (if users don't carefully check the config
before install the chart)

chart/README.md

@@ -34,7 +34,7 @@ cluster using the [Helm](https://helm.sh) package manager.
 
 ## Configuring Airflow
 
-All Airflow configuration parameters (equivalent of `airflow.cfg`) are stored in [values.yaml](https://github.com/apache/airflow/blob/master/chart/values.yaml) under the `config` key . The following code demonstrates how one would deny webserver users from viewing the config from within the webserver application. See the bottom line of the example:
+All Airflow configuration parameters (equivalent of `airflow.cfg`) are stored in [values.yaml](https://github.com/apache/airflow/blob/master/chart/values.yaml) under the `config` key . The following code demonstrates how one would allow webserver users to view the config from within the webserver application. See the bottom line of the example:
 
 ```yaml
 # Config settings to go into the mounted airflow.cfg
@@ -68,7 +68,7 @@ config:
     statsd_host: '{{ printf "%s-statsd" .Release.Name }}'
   webserver:
     enable_proxy_fix: 'True'
-    expose_config: 'False'   # <<<<<<<<<< BY DEFAULT THIS IS 'True' BUT WE CHANGE IT TO 'False' PRIOR TO INSTALLING THE CHART
+    expose_config: 'True'   # <<<<<<<<<< BY DEFAULT THIS IS 'False' BUT WE CHANGE IT TO 'True' PRIOR TO INSTALLING THE CHART
 ```
 
 Generally speaking, it is useful to familiarize oneself with the Airflow configuration prior to installing and deploying the service.
@@ -134,7 +134,7 @@ helm upgrade airflow . \
 
 ## Mounting DAGS using Git-Sync side car without Persistence
 
-This option will use an always running Git-Sync side car on every scheduler,webserver and worker pods. The Git-Sync side car containers will sync DAGs from a git repository every configured number of seconds. If you are using the KubernetesExecutor, Git-sync will run as an initContainer on your worker pods.
+This option will use an always running Git-Sync side car on every scheduler, webserver and worker pods. The Git-Sync side car containers will sync DAGs from a git repository every configured number of seconds. If you are using the KubernetesExecutor, Git-sync will run as an initContainer on your worker pods.
 
 ```bash
 helm upgrade airflow . \

chart/values.yaml

@@ -705,7 +705,6 @@ config:
     statsd_host: '{{ printf "%s-statsd" .Release.Name }}'
   webserver:
     enable_proxy_fix: 'True'
-    expose_config: 'True'
     rbac: 'True'
   celery:
     default_queue: celery