This commit integrates the Firefox Suggest Android component added in
bug 1850296 into Fenix, and adds:
* A Nimbus feature for Firefox Suggest.
* A secret setting to enable the Firefox Suggest feature, only visible
on the debug channel.
* Search settings for toggling sponsored and non-sponsored suggestions,
only visible when the Firefox Suggest feature is enabled.
When the feature is enabled, Fenix will ingest new suggestions in
the background, show the new Search settings, and show matching
suggestions in the awesomebar depending on those Search settings.
This bug adds telemetry for the print from menu feature. It adds the
probes print_failure, print_completed, print_tapped (for both share and
browsr menu), and share_menu_action for the print button on the share
sheet only. browser_menu_action for the print button was added in bug
1836780.
Additionally, Nimbus control for the browser print button and
share print button was added as browser-print-enabled and
share-print-enabled.
