Update ONLINE_CONTACT_TIMEOUT of Runner

This increases a timeout that Runner is considered
online. This is due to fact of two aspects that impact
how often we update DB entry:
- Runner being terminated by Workhorse, thus waiting
  on queue notification
- Rate of updating DB column

The timeout to consider Runner online (by DB)
needs to be aligned with these two timeouts,
otherwise runner can be wrongly assumed as not-online.

app/models/ci/runner.rb

@@ -23,10 +23,17 @@ module Ci
       project_type: 3
     }
 
-    ONLINE_CONTACT_TIMEOUT = 1.hour
+    # This `ONLINE_CONTACT_TIMEOUT` needs to be larger than
+    #   `RUNNER_QUEUE_EXPIRY_TIME+UPDATE_CONTACT_COLUMN_EVERY`
+    #
+    ONLINE_CONTACT_TIMEOUT = 2.hours
+
+    # The `RUNNER_QUEUE_EXPIRY_TIME` indicates the longest interval that
+    #   Runner request needs to be refreshed by Rails instead of being handled
+    #   by Workhorse
     RUNNER_QUEUE_EXPIRY_TIME = 1.hour
 
-    # This needs to be less than `ONLINE_CONTACT_TIMEOUT`
+    # The `UPDATE_CONTACT_COLUMN_EVERY` defines how often the Runner DB entry can be updated
     UPDATE_CONTACT_COLUMN_EVERY = (40.minutes..55.minutes).freeze
 
     AVAILABLE_TYPES_LEGACY = %w[specific shared].freeze