fix: fixing flaky test for debugtelemetry

[dietb]

Problem:
Tests in adk/server/adkrest/internal/services around the debug telemetry are flaky due to non-deterministic (map-based) ordering.

Solution:
Added deterministic sorting to both cases before test assertions. Now both the expected (tt.wantSessionSpans/tt.wantEventSpans) and actual (gotSessionSpans/gotEventSpans) results are sorted by name before comparison.

Testing Plan

go test ./... -count=5?

Unit Tests:

• I have added or updated unit tests for my change.
• All unit tests pass locally.

=== RUN   TestDebugTelemetryGetSpansBySessionID
=== RUN   TestDebugTelemetryGetSpansBySessionID/root_span_with_conversation_id
=== RUN   TestDebugTelemetryGetSpansBySessionID/child_span_with_conversation_id
=== RUN   TestDebugTelemetryGetSpansBySessionID/multiple_traces_with_same_session_id
=== RUN   TestDebugTelemetryGetSpansBySessionID/trace_with_spans_with_mixed_session_ids_session-1
=== RUN   TestDebugTelemetryGetSpansBySessionID/trace_with_spans_with_mixed_session_ids_session-2
=== RUN   TestDebugTelemetryGetSpansBySessionID/no_matching_session_id
=== RUN   TestDebugTelemetryGetSpansBySessionID/log_without_span
--- PASS: TestDebugTelemetryGetSpansBySessionID (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/root_span_with_conversation_id (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/child_span_with_conversation_id (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/multiple_traces_with_same_session_id (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/trace_with_spans_with_mixed_session_ids_session-1 (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/trace_with_spans_with_mixed_session_ids_session-2 (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/no_matching_session_id (0.00s)
    --- PASS: TestDebugTelemetryGetSpansBySessionID/log_without_span (0.00s)
=== RUN   TestDebugTelemetryGetSpansByEventID
=== RUN   TestDebugTelemetryGetSpansByEventID/single_span_and_log
=== RUN   TestDebugTelemetryGetSpansByEventID/multiple_spans
=== RUN   TestDebugTelemetryGetSpansByEventID/no_matching_span
=== RUN   TestDebugTelemetryGetSpansByEventID/log_without_span
--- PASS: TestDebugTelemetryGetSpansByEventID (0.00s)
    --- PASS: TestDebugTelemetryGetSpansByEventID/single_span_and_log (0.00s)
    --- PASS: TestDebugTelemetryGetSpansByEventID/multiple_spans (0.00s)
    --- PASS: TestDebugTelemetryGetSpansByEventID/no_matching_span (0.00s)
    --- PASS: TestDebugTelemetryGetSpansByEventID/log_without_span (0.00s)
=== RUN   TestDebugTelemetryLRU
--- PASS: TestDebugTelemetryLRU (0.00s)
PASS

Manual End-to-End (E2E) Tests:

This PR is for test cases only.

Checklist

• I have read the CONTRIBUTING.md document.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have manually tested my changes end-to-end.
• Any dependent changes have been merged and published in downstream modules.