[dynamic control] refactor OpampPolicyProvider for other PolicyProviders

[jackshirazi]

Description:

This is a straightforward refactor of behaviour in OpampPolicyProvider that other PolicyProviders will need to use (file and http providers). There are two separate refactors

• The policy snapshot from reading an incoming message is moved into an abstract superclass
• The mapping between policy ID and policy type (the incoming message has an ID but that maps into a concrete policy implementation after checking that the policy message is a valid message) is moved into a delegated helper class

Existing Issue(s):

#2868

Testing:

Already present, no changes needed

Documentation:

not needed for the refactoring

Outstanding items:

#2868

[Copilot]

Pull request overview

Refactors the dynamic-control OpAMP policy provider to extract reusable behavior needed by upcoming policy providers (e.g., file and HTTP providers), specifically around maintaining a current policy snapshot and mapping/validating incoming policy IDs into concrete policy types.

Changes:

• Introduced AbstractPolicyProvider to centralize “current policies snapshot” storage/update + update notifications.
• Introduced MappedPolicySourceConverter to encapsulate policy-id → policy-type mapping and validator-based conversion.
• Updated OpampPolicyProvider to extend the new base class and delegate mapping/validation to the new converter.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
dynamic-control/src/main/java/io/opentelemetry/contrib/dynamic/policy/OpampPolicyProvider.java	Refactored to use shared snapshot management and delegated policy mapping/validation.
dynamic-control/src/main/java/io/opentelemetry/contrib/dynamic/policy/MappedPolicySourceConverter.java	New helper to map incoming policy IDs to internal policy types and validate/convert sources into TelemetryPolicy.
dynamic-control/src/main/java/io/opentelemetry/contrib/dynamic/policy/AbstractPolicyProvider.java	New base class providing a thread-safe immutable snapshot of current policies plus update notification helper.