[AIRFLOW-6044] Standardize the Code Structure in kube_pod_operator.py

[kaxil]

https://issues.apache.org/jira/browse/AIRFLOW-6044

Make sure you have checked all steps below.

Jira

• My PR addresses the following Airflow Jira issues and references them in the PR title. For example, "[AIRFLOW-XXX] My Airflow PR"
  • https://issues.apache.org/jira/browse/AIRFLOW-6044

Description

• Here are some details about my PR, including screenshots of any UI changes:
  The execute method is before _init_. The order doesn't matter but for the sake of consistency across Airflow codebase, it would be ideal to standardize this.

Tests

• My PR adds the following unit tests OR does not need testing for this extremely good reason:
  Already covered

Commits

• My commits all reference Jira issues in their subject lines, and I have squashed multiple commits if they address the same issue. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

• In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public functions and the classes in the PR contain docstrings that explain what it does
  • If you implement backwards incompatible changes, please leave a note in the Updating.md so we can assign it to a appropriate release

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@6e26957). Click here to learn what that means.
The diff coverage is 97.29%.

@@            Coverage Diff            @@
##             master    #6639   +/-   ##
=========================================
  Coverage          ?   83.47%           
=========================================
  Files             ?      672           
  Lines             ?    37567           
  Branches          ?        0           
=========================================
  Hits              ?    31358           
  Misses            ?     6209           
  Partials          ?        0

Impacted Files	Coverage Δ
...rflow/contrib/operators/kubernetes_pod_operator.py	76.38% <97.29%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6e26957...048a4fd. Read the comment docs.