fix: aws_lambda test fix (#1383)

* fix: aws_lambda test fix

* use assert_equal

* lint

Author: xuan-cao-swi

instrumentation/aws_lambda/test/opentelemetry/instrumentation_test.rb

@@ -76,7 +76,8 @@
         _(last_span.hex_span_id.size).must_equal 16
         _(last_span.hex_trace_id.size).must_equal 32
         _(last_span.trace_flags.sampled?).must_equal true
-        _(last_span.tracestate.to_h.to_s).must_equal '{}'
+
+        assert_equal last_span.tracestate, {}
       end
     end
 
@@ -95,7 +96,8 @@
         _(last_span.hex_span_id.size).must_equal 16
         _(last_span.hex_trace_id.size).must_equal 32
         _(last_span.trace_flags.sampled?).must_equal true
-        _(last_span.tracestate.to_h.to_s).must_equal '{"otel"=>"ff40ea9699e62af2-01"}'
+
+        assert_equal last_span.tracestate, { 'otel' => 'ff40ea9699e62af2-01' }
       end
       event_v1['headers'].delete('traceparent')
       event_v1['headers'].delete('tracestate')
@@ -195,7 +197,8 @@
         _(last_span.hex_span_id.size).must_equal 16
         _(last_span.hex_trace_id.size).must_equal 32
         _(last_span.trace_flags.sampled?).must_equal true
-        _(last_span.tracestate.to_h.to_s).must_equal '{}'
+
+        assert_equal last_span.tracestate, {}
       end
     end