Fix mixup where SamplePathOverstroke wasn't added

- My sampleapp for the stroking bugs was inflight or something when
this change got made, so it didn't get added to this file.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2076283002

Review-Url: https://codereview.chromium.org/2076283002
1 file changed