Merge branch 'reduce_prometheus_adapter' into 'master'

Improve #has_metrics? and Environment#has_terminals?

See merge request gitlab-org/gitlab-ce!29847

app/models/deployment.rb

@@ -179,7 +179,7 @@ class Deployment < ApplicationRecord
   end
 
   def has_metrics?
-    prometheus_adapter&.can_query? && success?
+    success? && prometheus_adapter&.can_query?
   end
 
   def metrics

app/models/environment.rb

@@ -155,7 +155,7 @@ class Environment < ApplicationRecord
   end
 
   def has_terminals?
-    deployment_platform.present? && available? && last_deployment.present?
+    available? && deployment_platform.present? && last_deployment.present?
   end
 
   def terminals
@@ -163,7 +163,7 @@ class Environment < ApplicationRecord
   end
 
   def has_metrics?
-    prometheus_adapter&.can_query? && available?
+    available? && prometheus_adapter&.can_query?
   end
 
   def metrics