**Apache Airflow version**: 1.10.12

**Kubernetes version** : 1.17.9

**Environment**:

- **Cloud provider or hardware configuration**: Azure Kubernetes Service
- **OS** (e.g. from /etc/os-release): Linux
- **Install tools**: Helm chart (/chart in repo) 
- **Others**:

**What happened**:
Pod cannot run since `airflow-cleanup-pods` is not in $PATH
```
Error: failed to start container "airflow-cleanup-pods": Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"airflow-cleanup-pods\": executable file not found in $PATH": unknown
```

**What you expected to happen**: 
Cleanup job pod runs

<!-- What do you think went wrong? -->

**How to reproduce it**:
* Deploy Helm Chart
* Manually trigger `airflow-cleanup ` CronJob 
* See it cannot run since `airflow-cleanup-pods` is not in $PATH
airflow/cli/cli_parser.py
ARG_QUEUES = Arg(
    ("-q", "--queues"),
    help="Comma delimited list of queues to serve",
    default=conf.get('celery', 'DEFAULT_QUEUE'))
ARG_CONCURRENCY = Arg(
    ("-c", "--concurrency"),
    type=int,
    help="The number of worker processes",
    default=conf.get('celery', 'worker_concurrency'))
ARG_CELERY_HOSTNAME = Arg(
    ("-H", "--celery-hostname"),
    help=("Set the hostname of celery worker "
          "if you have multiple workers on a single machine"))
ARG_UMASK = Arg(
    ("-u", "--umask"),
    help="Set the umask of celery worker in daemon mode",
    default=conf.get('celery', 'worker_umask'))
ARG_BROKER_API = Arg(("-a", "--broker-api"), help="Broker API")
ARG_FLOWER_HOSTNAME = Arg(
    ("-H", "--hostname"),
    default=conf.get('celery', 'FLOWER_HOST'),
    help="Set the hostname on which to run the server")
ARG_FLOWER_PORT = Arg(
    ("-p", "--port"),
    default=conf.get('celery', 'FLOWER_PORT'),
    type=int,
    help="The port on which to run the server")
ARG_FLOWER_CONF = Arg(
    ("-c", "--flower-conf"),
    help="Configuration file for flower")