**Kiddush/chillul Hashem taken to mean showing the world that this is how Hashem's chosen people behaves:**

No, by definition: The gentile cannot be representative of a group he does not belong to.

**Kiddush/chillul Hashem taken to mean letting one self be killed rather than doing something forbidden:**

It depends (see Sanhedrin 74b).  If non-Jews are obligated in letting themselves be killed, then - Yes, by definition: If that is the label of an act, and he did that act, then it has that label.*

If non-Jews are not obligated in letting themselves be killed, then - No, they cannot perform the act of sanctifiying Hashem's name by being killed when they have no command to do so.

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<sup>* My head spins from reading my own words!</sup>