Use fixed binary value for test

The use of randomly generated values for pytest parameters may cause
errors in test explorer in Visual Studio Code. Specifically,
`test_return_value_serialization` test returns the following error when
a random parameter is used:

```
Test result not found for:
./tests/unit/conditions/test_return_value.py::test_return_value_serialization
[\xbd\x01\t\xecV\x05\x04\xe2\x9b(\xb6\xcef\xea\xa4\xfa]
```

Since the rest of values used in this test are fixed, there is no reason
to use a random value for bytes parameter.

tests/unit/conditions/test_return_value.py

@@ -41,7 +41,6 @@ def test_return_value_index():
         _ = ReturnValueTest(comparator=">", value="0", index="james")
 
 
-
 def test_return_value_index():
     test = ReturnValueTest(comparator=">", value="0", index=0)
     assert test.eval([1])
@@ -60,8 +59,6 @@ def test_return_value_index_tuple():
     assert not test.eval((-1,))
 
 
-
-
 def test_return_value_test_invalid_comparators():
     with pytest.raises(ReturnValueTest.InvalidExpression):
         _ = ReturnValueTest(comparator="eq", value=1)
@@ -216,7 +213,7 @@ def test_return_value_test_bool():
         "0xaDD9D957170dF6F33982001E4c22eCCdd5539118",  # string that is evaluated as int
         125,  # int
         1.223,  # float
-        os.urandom(16),  # bytes
+        b"\xe4\xe4u\x18\x03\x81i\xb74\x0e\xf5\xeb\x18\xf0\x0f\x82",  # bytes
         True,  # bool
         "True",  # bool as string
         (1, True, "love"),  # tuple