gptPreAuction Module: update to include MCM support

[mmoschovas]

Type of change

• Bugfix
• Feature
• New bidder adapter
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Does this change affect user-facing APIs or examples documented on http://prebid.org?
• Other

Description of change

The gptPreAuction module is not be compatible with the approach/format that Google uses for MCM (Multiple Customer Management). This update addresses the underlying issue by trimming the child ID from the ad unit name.

Ad Slot Definition: /123456,7654321/Ad_Unit_Name/1234567890

This is currently being passed via FPD as is under imp[].ext.data.pbadslot/adserver.adslot. SSPs will have issues reading this value due to the comma separated IDs.

Trimmed Name for FPD: /123456/Ad_Unit_Name/1234567890

This update also includes a config enablement via

pbjs.setConfig({
    gptPreAuction:{
        mcmEnabled: trrue
    }
});

[ChrisHuie]

@mmoschovas does a unit test need to be added for when MCM is enabled or is that already covered by the current testing?

[mmoschovas]

@ChrisHuie yes let me add a test in now. Hold off on merging until this is updated

[mmoschovas]

@ChrisHuie test have been added

[patmmccann]

very happy this merged but just a reminder 2nd reviewer required on non-vendor specific modules as well

[bretg]

FWIW - this was missing the doc update. Fixed in prebid/prebid.github.io#3206