Fix exception caused by missing keys in the ElasticSearch Record (apa…

…che#15163)

Optional LogRecord attributes cannot be added to log_format due to format exception.
This happened because ElasticSearch removes keys with null values from the record.

Configuration to reproduce. Optional attribute `exc_text` added to `log_format` and `json_fields`:
```
[logging]
remote_logging = True
log_format = [%%(asctime)s] {%%(filename)s:%%(lineno)d} %%(levelname)s - %%(message)s - %%(exc_text)s

[elasticsearch]
json_format = True
json_fields = asctime, filename, lineno, levelname, message, exc_text
```

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)

Refreshed provider's upcoming release with k8s retries (apache#15239)