Only allow TransportConfigUpdateAction after node has been set as bootstrapped

[cwperks]

Introduces another variable on DynamicConfigFactory called bootstrapped that behaves differently than the initialized variable. bootstrapped is a flag that signals to TransportConfigUpdateAction that it can start accepting updates.

There are 2 ways the security index can be created from scratch:

1. If plugins.security.allow_default_init_securityindex is set to true it will create the security index and load all yaml files
2. If plugins.security.allow_default_init_securityindex is set to false, the security index is not created on bootstrap and requires a user to run securityadmin to initialize security. When securityadmin is utilized, the cluster does depend on TransportConfigUpdateAction to initialize security so there still needs to be an avenue where this can update the config before initialized is set to true

This PR sets bootstrapped to false on node startup and explicitly sets it to true once its ok for TransportConfigUpdateAction to start accepting transport actions. In case 2) up above, it can be set to true before DynamicConfigFactory is initialized so that it can accept requests from securityadmin.

[codecov-commenter]

Codecov Report

Attention: 9 lines in your changes are missing coverage. Please review.

Comparison is base (7f1febf) 66.57% compared to head (b3b6de7) 65.19%.
Report is 5 commits behind head on main.

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Additional details and impacted files

@@            Coverage Diff             @@
##             main      #13      +/-   ##
==========================================
- Coverage   66.57%   65.19%   -1.38%     
==========================================
  Files         298      298              
  Lines       21189    21217      +28     
  Branches     3454     3460       +6     
==========================================
- Hits        14107    13833     -274     
- Misses       5364     5667     +303     
+ Partials     1718     1717       -1     

Files	Coverage Δ
.../opensearch/security/OpenSearchSecurityPlugin.java	84.48% <100.00%> (+0.04%)	⬆️
...ch/security/securityconf/DynamicConfigFactory.java	55.62% <ø> (ø)
...g/opensearch/security/support/ConfigConstants.java	95.23% <ø> (ø)
...tion/configupdate/TransportConfigUpdateAction.java	95.45% <66.66%> (-4.55%)	⬇️
...ecurity/configuration/ConfigurationRepository.java	73.03% <70.37%> (-5.88%)	⬇️

... and 37 files with indirect coverage changes