[Fixed] pets cannot be dna sampled from
[Changed] the order of some checks during dna sampling so that the
proper errors are always given

Change-Id: Id335de3c6fe3d61056888c4b4482e17967aa35b7
Merge "[Fixed] pets cannot be dna sampled from [Changed] the order of some checks during dna sampling so that the proper errors are always given" into unstable