For #21313: Renew fission metrics expiring in December

app/metrics.yaml

@@ -4722,12 +4722,13 @@ engine_tab:
     data_reviews:
       - https://github.com/mozilla-mobile/fenix/pull/17864
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
+      - https://github.com/mozilla-mobile/fenix/pull/21779#issuecomment-938089467
     data_sensitivity:
       - technical
     notification_emails:
       - android-probes@mozilla.com
       - skaspari@mozilla.com
-    expires: "2021-12-31"
+    expires: "2022-07-01"
   kill_foreground_age:
     type: timing_distribution
     time_unit: millisecond
@@ -4739,12 +4740,13 @@ engine_tab:
     data_reviews:
       - https://github.com/mozilla-mobile/fenix/pull/17864
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
+      - https://github.com/mozilla-mobile/fenix/pull/21779#issuecomment-938089467
     data_sensitivity:
       - technical
     notification_emails:
       - android-probes@mozilla.com
       - skaspari@mozilla.com
-    expires: "2021-12-31"
+    expires: "2022-07-01"
   kill_background_age:
     type: timing_distribution
     time_unit: millisecond
@@ -4756,12 +4758,13 @@ engine_tab:
     data_reviews:
       - https://github.com/mozilla-mobile/fenix/pull/17864
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
+      - https://github.com/mozilla-mobile/fenix/pull/21779#issuecomment-938089467
     data_sensitivity:
       - technical
     notification_emails:
       - android-probes@mozilla.com
       - skaspari@mozilla.com
-    expires: "2021-12-31"
+    expires: "2022-07-01"
   foreground_metrics:
     type: event
     description: |
@@ -4772,12 +4775,13 @@ engine_tab:
     data_reviews:
       - https://github.com/mozilla-mobile/fenix/pull/18747#issuecomment-815731764
       - https://github.com/mozilla-mobile/fenix/pull/19924#issuecomment-861423789
+      - https://github.com/mozilla-mobile/fenix/pull/21779#issuecomment-938089467
     data_sensitivity:
       - technical
     notification_emails:
       - android-probes@mozilla.com
       - skaspari@mozilla.com
-    expires: "2021-12-31"
+    expires: "2022-07-01"
     extra_keys:
       background_active_tabs:
         description: |