Bundled Elasticsearch throws node validation exception after Bitbucket upgrade

Issue Summary

After upgrading Bitbucket, the bundled Elasticsearch instance fails to start. In addition, the following error is found in the <BitbucketHome>/log/search/bitbucket_search.log file:

[2020-02-24T06:15:46,142][ERROR][o.e.b.Bootstrap ] [bitbucket_bundled]node validation exception
 Cluster name [bitbucket_search] subdirectory exists in data paths [<BITBUCKET_HOME>/shared/search/data/bitbucket_search]. All data under these paths must be moved up one directory to paths [<BITBUCKET_HOME>/shared/search/data]

Steps to Reproduce

1. Install and start Bitbucket 3.x (or 5.4.x) with a bundled Elasticsearch version
2. Upgrade Bitbucket to 6.10.1 and start the application

Expected Results

Bitbucket starts up with the bundled Elasticsearch.

Actual Results

The below exception is thrown in the bitbucket_search.log file:

[2020-02-24T06:15:46,142][ERROR][o.e.b.Bootstrap ] [bitbucket_bundled]node validation exception Cluster name [bitbucket_search] subdirectory exists in data paths [<BITBUCKET_HOME>/shared/search/data/bitbucket_search]. All data under these paths must be moved up one directory to paths [<BITBUCKET_HOME>/shared/search/data]

Workaround

Follow the steps provided in this KB article