Add canRemain method to TargetPoolAllocationDecider to move shards from local to remote pool for hot to warm tiering

[neetikasinghal]

Description

This pr adds canRemain method to TargetPoolAllocationDecider to move shards from local to remote pool for hot to warm tiering. Also, makes changes in the LocalShardsBalancer to not skip the shards tiered from hot to warm.

Related Issues

Related PR: #14891

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
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[github-actions]

❌ Gradle check result for dce0342: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for cc33864: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for e364d1e: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[neetikasinghal]

❌ Gradle check result for e364d1e: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

• org.opensearch.gateway.RecoveryFromGatewayIT.testShardStoreFetchMultiNodeMultiIndexesUsingBatchAction: flaky - [AUTOCUT] Gradle Check Flaky Test Report for RecoveryFromGatewayIT #14304

• org.opensearch.remotestore.WritableWarmIT.testWritableWarmBasic: looks like this test doesnt have a search node: https://github.com/opensearch-project/OpenSearch/blob/main/server/src/internalClusterTest/java/org/opensearch/remotestore/WritableWarmIT.java#L97: this needs an update in the test.

• org.opensearch.action.admin.cluster.allocation.ClusterAllocationExplainIT.testAllocationFilteringPreventsShardMove - will update the pr to add a reason when canRemain returns true

[github-actions]

❌ Gradle check result for c3a6aa1: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[neetikasinghal]

Thanks @neetikasinghal for the changes. Left some comments.

@shwetathareja thanks for your review, addressed your comments.

[github-actions]

❌ Gradle check result for 99d8510: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❕ Gradle check result for a6eee28: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[opensearch-trigger-bot]

The backport to 2.x 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/OpenSearch/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/OpenSearch/backport-2.x
# Create a new branch
git switch --create backport/backport-15010-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 c19cf88d266d15d6e8c69296cd0626099e562e38
# Push it to GitHub
git push --set-upstream origin backport/backport-15010-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/OpenSearch/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-15010-to-2.x.

[opensearch-trigger-bot]

The backport to 2.17 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/OpenSearch/backport-2.17 2.17
# Navigate to the new working tree
pushd ../.worktrees/OpenSearch/backport-2.17
# Create a new branch
git switch --create backport/backport-15010-to-2.17
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 c19cf88d266d15d6e8c69296cd0626099e562e38
# Push it to GitHub
git push --set-upstream origin backport/backport-15010-to-2.17
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/OpenSearch/backport-2.17

Then, create a pull request where the base branch is 2.17 and the compare/head branch is backport/backport-15010-to-2.17.

[neetikasinghal]

this change is also present in 2.17