[Telemetry] Send an event when users interact with the "set as default browser" card on the new tab

[tdsmith]

Description & Product Manager / Data Scientist User Story

In order to understand whether we can improve the effectiveness of each messaging surface we’re testing in the set-default experiment (#18796), we should understand how many people interact directly with our message.

As a data scientist, I want to know, using a Glean event, if a user interacted with the "set as default browser" card on the new tab page, which we will test in the branch described by #18375.

Distinct events should be sent for:

• selecting "set as default browser"
• dismissing the card using the X icon

What questions will you answer with this data?

• How many people clicked on the message that we presented?
• When they set to default and the system dialog shows up, how many users actually set us as default?
  • How many people simply close the dialog and do not follow through with setting to default?

Acceptance Criteria

• ENG files a DS JIRA request outlining their methodology.
• DS sign off on instrumentation methodology addressing product questions.
• Event pings can be queried via re:dash
• Event pings can be queried via amplitude
• We are sending telemetry events for the actions listed in the requirements
• We have documented the telemetry
• We have asked a data steward to review the telemetry

┆Issue is synchronized with this Jira Task

[lobontiumira]

Verified as fixed on a debug Nightly build #2015805929, GV 89.0a1-20210418092832 with Google Pixel (Android 10):

• ping: f9239b73-8659-4ed7-9402-3f047419b60c
• set_default_newtab_clicked event:

{
          "category": "set_default_newtab_experiment",
          "name": "set_default_browser_clicked",
          "timestamp": 3630
        }

• ping: 957c1071-3033-45e6-8fbe-2224695d6b95
• close_experiment_card_clicked event:

{
          "category": "set_default_newtab_experiment",
          "name": "close_experiment_card_clicked",
          "timestamp": 774
        }

Glean dashboard
telemetry logcat.txt