Add test to verify correct handling of Unicode.

Author: michaelsafyan

instrumentation-genai/opentelemetry-instrumentation-google-genai/tests/utils/test_dict_util.py

@@ -206,6 +206,38 @@ def test_flatten_with_mixed_structures():
         "foo.pydantic.int_value": 123,
     }
 
+def test_converts_tuple_with_json_fallback():
+    input_dict = {
+        "foo": ("abc", 123),
+    }
+    output = dict_util.flatten_dict(input_dict)
+    assert output == {
+        "foo.length": 2,
+        "foo[0]": "abc",
+        "foo[1]": 123,
+    }
+
+def test_converts_tuple_with_json_fallback():
+    input_dict = {
+        "foo": ("abc", 123),
+    }
+    output = dict_util.flatten_dict(input_dict)
+    assert output == {
+        "foo.length": 2,
+        "foo[0]": "abc",
+        "foo[1]": 123,
+    }
+
+def test_json_conversion_handles_unicode():
+    input_dict = {
+        "foo": ("❤️", 123),
+    }
+    output = dict_util.flatten_dict(input_dict)
+    assert output == {
+        "foo.length": 2,
+        "foo[0]": "❤️",
+        "foo[1]": 123,
+    }
 
 def test_flatten_with_complex_object_not_json_serializable():
     result = dict_util.flatten_dict(