(Partial) Revert "bug 1877836 - Remove GeckoView Streaming Telemetry"

This reverts commit 4559963.

This currently breaks at the very least update tasks like the push mode,
due to the metrics still being there in the other component, even though
they are "gone".

Author: badboy

probe_scraper/glean_checks.py

@@ -137,9 +137,13 @@ def check_for_duplicate_metrics(repositories, metrics_by_repo, emails):
                 if metric["history"][-1]["dates"]["last"] == last_timestamp:
                     metric_sources.setdefault(metric_name, []).append(dependency)
 
-        duplicate_sources = dict(
-            (k, v) for (k, v) in metric_sources.items() if len(v) > 1
-        )
+        duplicate_sources = {}
+        for (k, v) in metric_sources.items():
+            # Exempt cases when one of the sources is Geckoview Streaming to
+            # avoid false positive duplication accross app channels.
+            v = [dep for dep in v if "engine-gecko" not in dep]
+            if len(v) > 1:
+                duplicate_sources[k] = v
 
         if not len(duplicate_sources):
             continue