[Enhancement] Rename sample data index with prefix sample_*

[mihirsoni]

Is your feature request related to a problem? Please describe.
Sample data index are named with opensearch_dashboards_sample_data_* this works great but since there are lot of chances that customer might have actual logs named index opensearch_* or any other real logs. This could conflict since one can have template on opensearch_* open-search dashboards sample index to get applied

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Proposing to rename the sample data index name to prefix with sample and remove the opensearch_dashboards prefix to remove any accidential collision that could happen.

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[joshuarrrr]

Do we think there's benefit in any further attempts to prevent collisions?

• sample_data_*
• vs _sample_data_*
• vs __sample_data__*

[mihirsoni]

@joshuarrrr we can't start index name prefixed with _ and is not allowed characters in OpenSearch. _ is reserved for the internal APIs like _cat/indices, _cluster/status.

[joshuarrrr]

Are there other allowed characters we can use to further minimize collision risk?