Add creationDate to SamplingConfiguration

[seanzatzdev]

• Adds creationDate to SamplingConfiguration
• User generated creation dates are rejected.
• Adds a human readable field for the creation date to the XContent representation

[Copilot]

Pull Request Overview

Adds timestamp tracking functionality to SamplingConfiguration by introducing a creationDate field that automatically records when configurations are created, while preventing users from manually setting creation dates.

• Adds a creationDate field to the SamplingConfiguration record with automatic timestamp generation
• Implements validation to reject user-provided creation dates via context-aware parsing
• Updates serialization methods to include the new creationDate field

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
SamplingConfiguration.java	Adds creationDate field, updates constructors, parsing logic, and serialization methods
RestPutSampleConfigurationAction.java	Updates to use user-data aware parsing method to prevent manual creation date setting

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[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

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[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

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[masseyke]

You can just delete this (and adjust the array index of rawCreationTime above), right? It doesn't seem to actually be used.

[masseyke]

Oh I see it does make for a more meaningful user error message when they try to set creation_time.

[seanzatzdev]

Yeah, but also since we're using builder.timestampFieldsFromUnixEpochMillis(), it can lead to some weird errors if you don't add parsing instructions for both the raw and human readable fields. so i just added parsing instructions + ignored the human readable one up above

[masseyke]

I left a couple of minor comments, but LGTM