Disallow decrypt_kv jinja filter for fields marked as secret for pack config

[VineeshJain]

This PR addresses the issue where in pack config if fields are marked as secret: true and if user specifies jinja expression with filter decrypt_kv, the values are decrypted twice. This is due to the fact that for all fields marked as secret, the values are auto decrypted. Specifying an additional decrypt_kv filter causes issue.

The fix is to raise exceptions if decrypt_kv is specified for any fields marked secret. This is done for all three st2 pack config, Pack config from the WebUI and for st2ctl reload --reload-configs

[VineeshJain]

Here is the sample output for st2 pack config command:

(virtualenv) vagrant@ubuntu-xenial:~/st2$ st2 pack config hello_st2
name (secret):
name (secret): ***********************************
---
---
Do you want to preview the config in an editor before saving? [y]: n
---
Do you want me to save it? [y]: y
ERROR: 400 Client Error: Bad Request
MESSAGE: Validation Error: decrypt_kv jinja filter specified for auto decrypted fields marked with `secret: True` for url: http://127.0.0.1:9101/v1/configs/hello_st2

[VineeshJain]

Here is the output for st2ctl reload --register-configs command:

vijain@vijain-virtual-machine:~/workspace/st2$ st2ctl reload --register-configs
Registering content...[flags = --config-file /etc/st2/st2.conf --register-configs]
2019-06-11 16:45:58,557 INFO [-] Connecting to database "st2" @ "127.0.0.1:27017" as user "stackstorm".
2019-06-11 16:45:58,564 INFO [-] Successfully connected to database "st2" @ "127.0.0.1:27017" as user "stackstorm".
2019-06-11 16:45:59,196 INFO [-] =========================================================
2019-06-11 16:45:59,196 INFO [-] ############## Registering configs ######################
2019-06-11 16:45:59,196 INFO [-] =========================================================
2019-06-11 16:45:59,442 WARNING [-] Failed to register configs: Failed to register config "/opt/stackstorm/configs/hello_st2.yaml" for pack "hello_st2": Validation Error: decrypt_kv jinja filter specified for auto decrypted fields marked with `secret: True`
Traceback (most recent call last):
  File "/usr/bin/st2-register-content", line 22, in <module>
    sys.exit(content_loader.main(sys.argv[1:]))
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/content/bootstrap.py", line 408, in main
    register_content()
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/content/bootstrap.py", line 391, in register_content
    register_configs()
  File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/content/bootstrap.py", line 346, in register_configs
    raise e
ValueError: Failed to register config "/opt/stackstorm/configs/hello_st2.yaml" for pack "hello_st2": Validation Error: decrypt_kv jinja filter specified for auto decrypted fields marked with `secret: True`
##### st2 components status #####
st2actionrunner PID: 20873
st2actionrunner PID: 20875

[m4dcoder]

Where are the unit test(s)? Is this cover elsewhere? If so, please identify.

[m4dcoder]

@VineeshJain Please remove Address code review comment - from all of the commit title. Just focus the title on the actual change. Thanks.

[m4dcoder]

@VineeshJain You still need to fix the titles for the earlier commits.

[VineeshJain]

@VineeshJain You still need to fix the titles for the earlier commits.

I know, I am not done yet.