Refactor some methods in Prometheus model

- #update_errored? method def is redundant, already defined from state
machine
- #update_in_progress? moved to ApplicationStatus
- #ready_status becomes a constant. Previously it was extended in ee/ so
maybe that was why it's a instance method

app/models/clusters/applications/prometheus.rb

@@ -5,7 +5,8 @@ module Clusters
     class Prometheus < ActiveRecord::Base
       include PrometheusAdapter
 
-      VERSION = '6.7.3'.freeze
+      VERSION = '6.7.3'
+      READY_STATUS = [:installed, :updating, :updated, :update_errored].freeze
 
       self.table_name = 'clusters_applications_prometheus'
 
@@ -24,20 +25,8 @@ module Clusters
         end
       end
 
-      def ready_status
-        [:installed, :updating, :updated, :update_errored]
-      end
-
       def ready?
-        ready_status.include?(status_name)
-      end
-
-      def update_in_progress?
-        status_name == :updating
-      end
-
-      def update_errored?
-        status_name == :update_errored
+        READY_STATUS.include?(status_name)
       end
 
       def chart

app/models/clusters/concerns/application_status.rb

@@ -77,6 +77,10 @@ module Clusters
       def available?
         installed? || updated?
       end
+
+      def update_in_progress?
+        updating?
+      end
     end
   end
 end