gptPreAuction module doesn't respect MCM parameter in default mode

[muuki88]

Type of issue

bug

Description

Steps to reproduce

1. Build a prebid distribution with the gptPreAuction module ( https://docs.prebid.org/dev-docs/modules/gpt-pre-auction.html )
2. Configure it with mcmEnabled

gptPreAuction: {
   mcmEnabled: true
}

3. Request an ad slot with an MCM flavoured ad unit path, e.g. /123,456/my-ad-unit . Where 456 is the network child id

Expected results

Prebid.js/modules/gptPreAuction.js

Lines 119 to 124 in 24306f3

	// find all GPT slots with this name
	var gptSlots = window.googletag.pubads().getSlots().filter(slot => slot.getAdUnitPath() === adServerAdSlot);
	if (gptSlots.length === 0) {
	return; // should never happen
	}

finds the correct ad slot and does not run in the "this should never happen" case

Actual results

The slot.getAdUnitPath() method returns /123,456/my-ad-unit , while adServerSlot is /123/my-ad-unit , which are not equal.

Setting mcmEnabled: false solves the issue.

Platform details

Prebid 9.8.0