Adding a field with a default value

Hi. When adding a test field with a default value (false). Binary view this field is added.
This behavior is different from the behavior in java.
https://developers.google.com/protocol-buffers/docs/proto3#default
Example:
**{"test": null}**
dart
[186, 6, 0]
java
[-70, 6, 0]
That's right, expected result.

**{"test": true}**
dart
[186, 6, 2, 40, 1]
java
[-70, 6, 2, 40, 1]
That's right, expected result.

**{"test": false}**
dart
[186, 6, **2, 40, 0**]
java
[-70, 6, 0]
in java the correct result in dart is not

Start with the proto3 default-value documentation and the supplied Dart and Java binary examples. Compare how a false value is encoded when the field has a default, then verify that Dart produces the same result as Java for null, true, and false cases.

Written by the indexing model from the issue text.