Enable on-demand DAST scan feature flag by default

What does this MR do?

this merge request enables security_on_demand_scans_feature_flag feature flag by default as per discussion (slack, gitlab).

we feel like we're ready to enable the feature flag by default because the feature has been verified and seems to be working as expected. we're going to keep all the logic associated with this feature flag and enable it by default in %13.3, which would will allow us to disable it later on if we need to. early in %13.4, we'll remove the feature flag altogether.

to remove a the feature flag if you've already set it locally you should run the following command.

echo "Feature.remove(:security_on_demand_scans_feature_flag)" | bundle exec rails c

Related Issue(s)

#235105 (closed)

Notes

• follow up merge request to reduce feature flag surface area
• documentation

Screenshot(s)

master feature flag not enabled

default-on-demand-dast-scan-feature-to-true-235105 feature flag not enabled

Screen_Recording_2020-08-13_at_3.56.33_pm

ignore paused job. my local runner requires me to to pause and unpause to pick up jobs. i verified the job ran but the video was too long to upload.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team