A recent change modified some comment editing UX. As a consequence, the
save button disabled state was erroneously based entirely on whether or
not the comment message had changed.
With this change:
- Save disabled state on a comment takes into account resolved state
- The resolved checkbox is always visible on an expanded draft comment
- When the resolved checkbox is modified on a non-`editing` draft
comment, it is saved immediately
Bug: Issue 6023
Change-Id: I40b0b280129e5a76c13e38c97525f91a8e56482d
46a6c8eca2