Add a preview image to the color mode preference.

For high-color displays, it's desirable to have a preview of the
impact the user's color preference will have on images.  This commit
adds that functionality to ColorModePreferenceFragment by extending
RadioButtonPickerFragment to support static content.

The image used here is a placeholder pending UX.

Bug: 73670362
Test: Added a test verifying that the preview is added correctly.
Change-Id: Id54316bbef6a22291a8e8acbda5fcb2839b88c23