Minor Duplication: unnecessary core-icon-button declaration block to style the fill color of the favorite icon

[lozandier]

For some reason, two declarations blocks were used to style core-icon-button instead of one. If there was an explicit reason for this, it remained unaddressed.

If I'm correct there wasn't a strong reason for the second declaration block, it may be better to have the style code snippet presented similar to the code snippet below this paragraph:

 core-icon-button {
    position: absolute;
    top: 3px;
    right: 3px;
    fill: #636363;
  }

  :host([favorite]) core-icon-button {
    fill: #da4336;
 }