Update Auto DevOps STAGING and CANARY documentation for clarity

doc/topics/autodevops/customize.md

@@ -520,8 +520,7 @@ on the default branch. However, there are cases where you might want to use a
 staging environment, and deploy to production manually. For this scenario, the
 `STAGING_ENABLED` environment variable was introduced.
 
-If you define `STAGING_ENABLED`, such as setting `STAGING_ENABLED` to
-`1` as a CI/CD variable, then GitLab automatically deploys the application
+If you define `STAGING_ENABLED` with a non-empty value, then GitLab automatically deploys the application
 to a `staging` environment, and creates a `production_manual` job for
 you when you're ready to manually deploy to production.
 
@@ -532,8 +531,7 @@ you when you're ready to manually deploy to production.
 You can use a [canary environment](../../user/project/canary_deployments.md) before
 deploying any changes to production.
 
-If you define `CANARY_ENABLED` in your project, such as setting `CANARY_ENABLED` to
-`1` as a CI/CD variable, then two manual jobs are created:
+If you define `CANARY_ENABLED` with a non-empty value, then two manual jobs are created:
 
 - `canary` - Deploys the application to the canary environment.
 - `production_manual` - Manually deploys the application to production.