googlesamples/android-WatchFace: AAPT build error

[codingjeremy]

Original issue created by @IgorGanapolsky in the old repo location (googlesamples/android-WatchFace):

Hello,
I am getting the following build error:

AAPT: error: duplicate value for resource 'attr/progress' with config ''.

The incremental values.xml look like this:
<declare-styleable name="SeekArc"><attr format="dimension" name="arcWidth"/><attr format="color" name="arcColor"/><attr format="integer" name="startAngle"/><attr format="integer" name="sweepAngle"/><attr format="integer|reference" name="maxProgress"/><attr format="integer|reference" name="progress"/><attr format="color" name="progressColor"/><attr format="boolean" name="roundCorner"/><attr format="color" name="thumbColor"/><attr format="dimension" name="thumbRadius"/><attr format="string" name="seekDirection"/></declare-styleable>