SAST template missing propagation for SAST_GITLEAKS_ENTROPY_LEVEL ENV variable

Summary

Our SAST template is currently missing ENV propagation support for our secrets analyzers entropy detection: SAST_GITLEAKS_ENTROPY_LEVEL. Because of this, a user is unable to configure entropy detection unless calling the secrets analyzer directly

Steps to reproduce

1. Add high-entropy string to codebase; i.e. Reu3eitiotaR1ucooyoopeo3eseeshahee8aquaPh0Iadohgh8gatoovie6phoobooLix7vae7ru5ooVez5vuaW6phe9ze7Ma4ao
2. Add SAST.gitlab-ci.yml inclusion to .gitlab-ci.yml
3. Run pipeline with variable: SAST_GITLEAKS_ENTROPY_LEVEL set to a low entropy threshold; i.e. "1.0"

Example Project

What is the current bug behavior?

SAST_GITLEAKS_ENTROPY_LEVEL Entropy variable is ignored when run through template

What is the expected correct behavior?

SAST_GITLEAKS_ENTROPY_LEVEL should be respected when passed to sast job, allowing detection of high entropy strings

Output of checks

This bug happens on GitLab.com

Possible fixes

Add SAST_GITLEAKS_ENTROPY_LEVEL to list of propagated variables: https://gitlab.com/gitlab-org/gitlab-ee/blob/v11.11.0-rc2-ee/lib/gitlab/ci/templates/Security/SAST.gitlab-ci.yml#L33-45