I got everything to work, and I have a script so I can build the bundles for Android.

using UnityEditor;
using UnityEngine;
using System.Collections;

public class ExportResource : MonoBehaviour
{
	[MenuItem("Signature Creative/Build AssetBundle From Selection")]
	public static void ExportRes()
	{
		// Bring up save panel
		string path = EditorUtility.SaveFilePanel("Save Resource", "", "Package", "unity3d");
		if (path.Length != 0)
		{
			// Build the resource file from the active selection.
			Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
			
			BuildPipeline.BuildAssetBundle(Selection.activeObject, selection, path, BuildAssetBundleOptions.CollectDependencies | BuildAssetBundleOptions.CompleteAssets, BuildTarget.Android);	
			Selection.objects = selection;
		}
	}
}

The problem is: When Unity created the entire example for us, they did NOT use: BuildTarget.Android in the BuildAssetBundle method. How could I find their prefabs so I can rebuild the assets for the platforms I want?

The CharacterCustomization demo has a script that does it - modify that script to your needs, don’t pick the prefabs by hand.