Rename pushover integration association

Renames project association from pushover_service to
pushover_integration.

app/models/integration.rb

@@ -48,7 +48,7 @@ class Integration < ApplicationRecord
     flowdock
     hangouts_chat
     irker
-    packagist pipelines_email pivotaltracker
+    packagist pipelines_email pivotaltracker pushover
   ].to_set.freeze
 
   def self.renamed?(name)

app/models/project.rb

@@ -181,7 +181,7 @@ class Project < ApplicationRecord
   has_one :packagist_integration, class_name: 'Integrations::Packagist'
   has_one :pipelines_email_integration, class_name: 'Integrations::PipelinesEmail'
   has_one :pivotaltracker_integration, class_name: 'Integrations::Pivotaltracker'
-  has_one :pushover_service, class_name: 'Integrations::Pushover'
+  has_one :pushover_integration, class_name: 'Integrations::Pushover'
   has_one :redmine_service, class_name: 'Integrations::Redmine'
   has_one :slack_service, class_name: 'Integrations::Slack'
   has_one :slack_slash_commands_service, class_name: 'Integrations::SlackSlashCommands'

spec/lib/gitlab/import_export/all_models.yml

@@ -385,7 +385,7 @@ project:
 - buildkite_integration
 - bamboo_integration
 - teamcity_service
-- pushover_service
+- pushover_integration
 - jira_service
 - redmine_service
 - youtrack_service

spec/models/project_spec.rb

@@ -42,7 +42,7 @@ RSpec.describe Project, factory_default: :keep do
     it { is_expected.to have_one(:unify_circuit_service) }
     it { is_expected.to have_one(:webex_teams_service) }
     it { is_expected.to have_one(:packagist_integration) }
-    it { is_expected.to have_one(:pushover_service) }
+    it { is_expected.to have_one(:pushover_integration) }
     it { is_expected.to have_one(:asana_integration) }
     it { is_expected.to have_many(:boards) }
     it { is_expected.to have_one(:campfire_integration) }