For #976: Adds telemetry for library

[sblatz]

Pull Request checklist

• Quality: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
• Tests: This PR includes thorough tests or an explanation of why it does not
• Changelog: This PR includes a changelog entry or does not need one
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features

[sblatz]

Request for data collection review form

All questions are mandatory. You must receive review from a data steward peer on your responses to these questions before shipping new data collection.

1. What questions will you answer with this data?

• Understand how often and when and what they access in the library

2. Why does Mozilla need to answer these questions? Are there benefits for users? Do we need this information to address product or business requirements?

• It will help us understand how useful the library concept is

3. What alternative methods did you consider to answer these questions? Why were they not sufficient?

• N/A (These are baseline metrics)

4. Can current instrumentation answer these questions?

• Currently no, as these are some of the first metrics we're recording

5. List all proposed measurements and indicate the category of data collection for each measurement, using the Firefox data collection categories on the found on the Mozilla wiki.

• All data is Category 2.

6. How long will this data be collected?

Until 04/01/2020 (renewed thereafter)

7. What populations will you measure?

• All release, beta, and nightly users with telemetry enabled.

8. Please provide a general description of how you will analyze this data.

• Glean / Amplitude

9. Where do you intend to share the results of your analysis?

• Only on Glean, Amplitude and with mobile teams.

[boek]

R+, just add documentation for the possible values of item for selected_item

Data Review Form (to be filled by Data Stewards)

1. Is there or will there be documentation that describes the schema for the ultimate data set available publicly, complete and accurate?
   Yes, in metrics.yaml

2. Is there a control mechanism that allows the user to turn the data collection on and off? (Note, for data collection not needed for security purposes, Mozilla provides such a control mechanism) Provide details as to the control mechanism available.
   Yes, Fenix data controls

3. If the request is for permanent data collection, is there someone who will monitor the data over time?**
   No, @vesta0 will monitor and it has expiry

4. Using the category system of data types on the Mozilla wiki, what collection type of data do the requested measurements fall under? **
   Type 2, interaction with the library provided by Fenix

5. Is the data collection request for default-on or default-off?
   Default on

6. Does the instrumentation include the addition of any new identifiers (whether anonymous or otherwise; e.g., username, random IDs, etc. See the appendix for more details)?
   No

7. Is the data collection covered by the existing Firefox privacy notice?
   Yes

8. Does there need to be a check-in in the future to determine whether to renew the data? (Yes/No) (If yes, set a todo reminder or file a bug if appropriate)**
   No, has expiry

9. Does the data collection use a third-party collection tool? If yes, escalate to legal.
   No