[BUG] Existing BWC examples do not support more than one revision

[peternied]

Describe the bug
All OpenSearch components should be running backwards compatibility tests to ensure compatibility as incrementing version numbers and modify features.

In the Security codebase as we are focusing on 2.1 the process to setup the cluster for BWC is hardcoded to allow for a single previous and current version. This prevent us from following the guidance to support BWC testing for 1.3.0 and 2.0.0 versions of OpenSearch and the Security plugin.

String bwcVersion = "1.3.0.0"; // Should be an array of versions
String baseName = "securityBwcCluster"
String bwcFilePath = "src/test/resources/"
String projectVersion = "2.0.0.0"

2.times {i ->
    testClusters {
        "${baseName}$i" {
            testDistribution = "ARCHIVE"
        versions = ["1.3.0","2.0.0"] // Bad practice that duplicates information
            numberOfNodes = 3
            plugin(provider(new Callable<RegularFile>() {
                @Override
                RegularFile call() throws Exception {

See bwc-test/build.gradle in the security codebase for the full implementation

Expected behavior
We should have a better mechanism or central process to allow for appending additional versions of BWC tests as the version of the codebase increments.

Additional the distribution of these mechanism should be built into the gradle plugin that all component teams use so its easy to pick up and get updates as feature are added/introduced.