add new amp-analytics triggers for Core Web Vitals in googletagmanager

According to the [example](https://amp.dev/documentation/examples/advertising-analytics/tracking_core_web_vitals/?format=websites), it is available for amp-analytics type googleanalytics, but we use googletagmanager

We implemented it, but we still do not see that it records information, do you think it will be possible with GTM + SSR?

https://koko.news/mobile/eat/5-simple-ways-to-help-improve-your-blood-sugar-regulation-20210205-0001.html


In GTM the corresponding variables were declared and sent through custom dimensions, but we don't see that it registers values.

Start by comparing the linked amp-analytics Core Web Vitals example for googleanalytics with the googletagmanager configuration and the reported GTM variables and custom dimensions. Confirm whether GTM with SSR can record the values, and consider the work complete when Core Web Vitals data is visibly registered through the documented setup.

Written by the indexing model from the issue text.