[AIRFLOW-5974] AIP-21 Change import paths for celery modules

[yqian1991]

part of AIP-21, Change import paths for celery modules

Issue link: AIRFLOW-5974

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• Description above provides context of the change
• Commit message/PR title starts with [AIRFLOW-NNNN]. AIRFLOW-NNNN = JIRA ID^*
• Unit tests coverage for changes (not needed for documentation changes)
• Commits follow "How to write a good git commit message"
• Relevant documentation is updated including usage instructions.
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^* For document-only changes commit message can start with [AIRFLOW-XXXX].

---

In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in UPDATING.md.
Read the Pull Request Guidelines for more information.

[codecov-io]

Codecov Report

Merging #7167 into master will increase coverage by 0.59%.
The diff coverage is 71.87%.

@@            Coverage Diff             @@
##           master    #7167      +/-   ##
==========================================
+ Coverage   84.91%   85.51%   +0.59%     
==========================================
  Files         723      759      +36     
  Lines       39546    39936     +390     
==========================================
+ Hits        33581    34150     +569     
+ Misses       5965     5786     -179

Impacted Files	Coverage Δ
airflow/contrib/sensors/celery_queue_sensor.py	0% <0%> (-82.15%)	⬇️
airflow/providers/celery/sensors/celery.py	82.14% <82.14%> (ø)
...rflow/contrib/sensors/sagemaker_training_sensor.py	0% <0%> (-100%)	⬇️
airflow/api/client/local_client.py	92% <0%> (-8%)	⬇️
airflow/api/client/api_client.py	63.15% <0%> (-1.55%)	⬇️
...rflow/contrib/operators/kubernetes_pod_operator.py	97.64% <0%> (-1.15%)	⬇️
airflow/gcp/hooks/dataflow.py	88.37% <0%> (-0.92%)	⬇️
airflow/operators/python_operator.py	95.13% <0%> (-0.67%)	⬇️
airflow/cli/commands/dag_command.py	85.9% <0%> (-0.31%)	⬇️
airflow/contrib/sensors/emr_base_sensor.py	100% <0%> (ø)	⬆️
... and 94 more

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[yqian1991]

Closing this, seems like a duplicate work of another pr