gtag() is getting overriden when using multiple gtm or ga with different dataLayers

[huang-julien]

reproduction
nuxt/scripts#173

When using dataLayers, gtag defined by tpc is overriden due to window.gtag=function gtag(){window.dataLayers['{{dataLayerName}}'].push(arguments);} at

third-party-capital/src/third-parties/google-analytics/data.json

Line 15 in 92b1495

"code": "window.dataLayers=window.dataLayers||{};window.dataLayers['{{dataLayerName}}']=window.dataLayers['{{dataLayerName}}']||[];window.gtag=function gtag(){window.dataLayers['{{dataLayerName}}'].push(arguments);};window.gtag('js',new Date());window.gtag('config','{{id}}')",

This prevent users to have multiple dataLayers.

[huang-julien]

Can we drop gtag() and let users handle the push function by themselves ? this is probably safer as gtag() is only a wrapper around the datalayer's push function