Secure onboarding progress trial actions

What does this MR do and why?

Add high-conversion trial actions to Continuous Onboarding database for Secure events

Related to #345173

Query plan for the distinct security scan_types https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/7758/commands/27606

Database migration

$ bundle exec rake db:migrate:down VERSION=20211220174504

$ bundle exec rake db:migrate:up VERSION=20211220174504
== 20211220174504 AddSecureScanningActionsToOnboardingProgresses: migrating ===
-- change_table(:onboarding_progresses, {:bulk=>true})
   -> 0.0356s
== 20211220174504 AddSecureScanningActionsToOnboardingProgresses: migrated (0.0357s) 

== 20211220174504 AddSecureScanningActionsToOnboardingProgresses: reverting ===
-- remove_column(:onboarding_progresses, :secure_api_fuzzing_run_at, :datetime_with_timezone, {})
   -> 0.0020s
-- remove_column(:onboarding_progresses, :secure_cluster_image_scanning_run_at, :datetime_with_timezone, {})
   -> 0.0019s
-- remove_column(:onboarding_progresses, :secure_coverage_fuzzing_run_at, :datetime_with_timezone, {})
   -> 0.0019s
-- remove_column(:onboarding_progresses, :secure_secret_detection_run_at, :datetime_with_timezone, {})
   -> 0.0022s
-- remove_column(:onboarding_progresses, :secure_dast_run_at, :datetime_with_timezone, {})
   -> 0.0019s
-- remove_column(:onboarding_progresses, :secure_container_scanning_run, :datetime_with_timezone, {})
   -> 0.0018s
-- remove_column(:onboarding_progresses, :secure_dependency_scanning_run_at, :datetime_with_timezone, {})
   -> 0.0020s
== 20211220174504 AddSecureScanningActionsToOnboardingProgresses: reverted (0.0390s) 

How to set up and validate locally

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.