Fixes password assignment for integTest when using remote cluster

[DarshitChanpura]

• Related to https://github.com/opensearch-project/index-management/issues/1073

Since the password system property was already set the value of admin, this wouldn't be changed later. This was a flaw in https://github.com/opensearch-project/index-management/pull/1088. This PR fixes that by doing conditional assignment at 1 place.

CheckList:

• [x] Commits are signed per the DCO using --signoff

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[DarshitChanpura]

Can one of the maintainers create a backport 2.12 label, so that this change gets backported to 2.12?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (08b3152) 74.87% compared to head (8586e95) 74.87%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1091 +/- ## ========================================= Coverage 74.87% 74.87% + Complexity 2814 2811 -3 ========================================= Files 367 367 Lines 16522 16522 Branches 2363 2363 ========================================= Hits 12371 12371 - Misses 2847 2849 +2 + Partials 1304 1302 -2 ```

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[opensearch-trigger-bot[bot]]

The backport to 2.12 failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/index-management/backport-2.12 2.12
# Navigate to the new working tree
pushd ../.worktrees/index-management/backport-2.12
# Create a new branch
git switch --create backport/backport-1091-to-2.12
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 027509e3c7ca25fd3f910d48dbd3456597d0a9e1
# Push it to GitHub
git push --set-upstream origin backport/backport-1091-to-2.12
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/index-management/backport-2.12

Then, create a pull request where the base branch is 2.12 and the compare/head branch is backport/backport-1091-to-2.12.

[bowenlan-amzn]

@DarshitChanpura can you do a manual backport please actually I do see the PR created...

[DarshitChanpura]

@bowenlan-amzn created a manual backport to 2.12: #1094