feat: include writerId as part of trace id

[agrawal-siddharth]

No description provided.

[gemini-code-assist]

Code Review

This pull request refactors trace ID generation in the BigQuery Storage write client by passing the individual clientId and traceId components to ConnectionWorker instead of pre-constructing the full trace ID in StreamWriter. This allows ConnectionWorker to dynamically build the full trace ID using the writerId and client library version. A critical issue was identified in the ConnectionWorker constructor where this.writerId is referenced before it is initialized; using the local writerId variable instead will prevent potential null pointer or uninitialized field issues.

[gemini-code-assist]

In the constructor, writerId is available as a local variable (as seen in the TelemetryMetrics constructor call on line 663). Using this.writerId here might refer to an uninitialized field (which would be null) if the field assignment this.writerId = writerId; has not occurred yet. Please use the local variable writerId instead of this.writerId to ensure the correct value is used.

Suggested change

	String fullTraceId = getFullTraceId(clientlibId, this.writerId, traceId);
	String fullTraceId = getFullTraceId(clientlibId, writerId, traceId);