Disable a failed PPL query fallback to v2 by default

[LantaoJin]

Description

Disable a failed PPL query fallback to v2 by default: plugins.calcite.fallback.allowed=false

Related Issues

Resolves #3942

Check List

• New functionality includes testing.
• New functionality has been documented.
• New functionality has javadoc added.
• New functionality has a user manual doc added.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

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[LantaoJin]

#3921 seems didn't handle the calcite fallback disable case. I got failures following if disable calcite fallback.

PPLPermissionsIT > testUserWithoutMappingPermissionCannotGetFieldMappings() FAILED
    java.lang.AssertionError: expected:<403> but was:<500>
        at org.junit.Assert.fail(Assert.java:89)
        at org.junit.Assert.failNotEquals(Assert.java:835)
        at org.junit.Assert.assertEquals(Assert.java:647)
        at org.junit.Assert.assertEquals(Assert.java:633)
        at org.opensearch.sql.security.PPLPermissionsIT.testUserWithoutMappingPermissionCannotGetFieldMappings(PPLPermissionsIT.java:568)
org.opensearch.sql.security.PPLPermissionsIT.testUserWithoutSearchPermissionCannotSearchIndex(): FAILURE 0.336s

PPLPermissionsIT > testUserWithoutSearchPermissionCannotSearchIndex() FAILED
    java.lang.AssertionError: expected:<403> but was:<500>
        at org.junit.Assert.fail(Assert.java:89)
        at org.junit.Assert.failNotEquals(Assert.java:835)
        at org.junit.Assert.assertEquals(Assert.java:647)
        at org.junit.Assert.assertEquals(Assert.java:633)
        at org.opensearch.sql.security.PPLPermissionsIT.testUserWithoutSearchPermissionCannotSearchIndex(PPLPermissionsIT.java:550)

To unblock this PR before code freeze. I allowed fallback in PPLPermissionsIT.java. cc @penghuo @vamsimanohar

[vamsimanohar]

I am ok for now, lets fix this after the code freeze. I haven't tested without fallback.

[penghuo]

backport 2.19-dev?

[opensearch-trigger-bot]

The backport to 2.19-dev 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/sql/backport-2.19-dev 2.19-dev
# Navigate to the new working tree
pushd ../.worktrees/sql/backport-2.19-dev
# Create a new branch
git switch --create backport/backport-3952-to-2.19-dev
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 7892b90bb5fe80bbeb60a3200d94177dfe20d839
# Push it to GitHub
git push --set-upstream origin backport/backport-3952-to-2.19-dev
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/sql/backport-2.19-dev

Then, create a pull request where the base branch is 2.19-dev and the compare/head branch is backport/backport-3952-to-2.19-dev.