Add alias method usage_ping_enabled?

Related issue #333269 (closed)

What does this MR do?

• In SubmitUsagePingService we check if Gitlab::CurrentSettings.usage_ping_enabled?

• Gitlab::CurrentSettings.usage_ping_enabled? goes to Gitlab::CurrentSettings and forwards the usage_ping_enabled? method to ApplicationSettings. ApplicationSettings is including ApplicationSettingImplementation which makes sure that we can override configs from config files or the database.

  • In ApplicationSettingImplementation we have a method where we override usage_ping_enabled to account for the logic to first check if the config file has changed to false and then later check the database
  • However, when calling CurrentSettings.usage_ping_enabled? we do this with the ? version (which comes from ActiveRecord) so we don't go to the overridden usage_ping_enabled method and therefore we ignore the config settings.

• With this MR we add alias_method :usage_ping_enabled?, :usage_ping_enabled This way we have the usage_ping_enabled? available for CurrentSettings module.

Testing scenarios

Scenario 1

Database enabled config disabled

Usage Ping should not be generated and sent

Scenario 2

Database disabled config enabled

Usage Ping should not be generated and sent

Scenario 3

Database disabled config disabled

Usage Ping should not be generated and sent

Scenario 3

Database enabled, config enabled

Usage Ping should be generated and sent

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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Security

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