Use splunk edit user command to update admin password on one pod of the searchheadcluster

[mcaci]

Description

The aim of this PR is to change the way the admin password is changed in the searchheadcluster to address issue
#1554

Key Changes

• Replace the action of changing the admin password from calling "opt/splunk/bin/splunk cmd splunkd rest" to calling "opt/splunk/bin/splunk edit user admin".
• Call the action splunk edit user on one pod of the searchheadcluster and let the replication propagate the change.

Testing and Verification

We run this version of the code in our clusters up to production

Related Issues

#1554

PR Checklist

• Code changes adhere to the project's coding standards.
• Relevant unit and integration tests are included.
• Documentation has been updated accordingly.
• All tests pass locally.
• The PR description follows the project's guidelines.

[patrykw-splunk]

Hey, thanks a lot for contribution. We will take a look on that as soon as possible