Rename span-suppression-strategy configuration with backward compatibility

[Abhilash-Garapati]

This PR renames the configuration key

otel.instrumentation.experimental.span-suppression-strategy

to the new name:

otel.instrumentation.common.experimental.span-suppression-strategy

This follows the naming conventions suggested in issue #15566.

Changes included:

• Updated all internal references and usages to the new config key.
• Added backward compatibility: the old key still works but triggers a warning log.
• No behavior changes for users who haven't migrated yet.

Tested locally with successful build.

Please review and let me know if any additional updates are needed.

[linux-foundation-easycla]

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