Prefer to use symbols for feature flag names

This prefers to use symbols where possible
for feature flag names

app/models/ci/build_dependencies.rb

@@ -45,7 +45,7 @@ module Ci
     end
 
     def valid_local?
-      return true if Feature.enabled?('ci_disable_validates_dependencies')
+      return true if Feature.enabled?(:ci_disable_validates_dependencies)
 
       local.all?(&:valid_dependency?)
     end

doc/administration/job_artifacts.md

@@ -351,7 +351,7 @@ you can flip the feature flag from a Rails console.
 1. Flip the switch and disable it:
 
    ```ruby
-   Feature.enable('ci_disable_validates_dependencies')
+   Feature.enable(:ci_disable_validates_dependencies)
    ```
 
 **In installations from source:**
@@ -366,7 +366,7 @@ you can flip the feature flag from a Rails console.
 1. Flip the switch and disable it:
 
    ```ruby
-   Feature.enable('ci_disable_validates_dependencies')
+   Feature.enable(:ci_disable_validates_dependencies)
    ```
 
 ## Set the maximum file size of the artifacts

doc/administration/job_logs.md

@@ -128,13 +128,13 @@ sudo -u git -H bin/rails console -e production
 **To check if incremental logging (trace) is enabled:**
 
 ```ruby
-Feature.enabled?('ci_enable_live_trace')
+Feature.enabled?(:ci_enable_live_trace)
 ```
 
 **To enable incremental logging (trace):**
 
 ```ruby
-Feature.enable('ci_enable_live_trace')
+Feature.enable(:ci_enable_live_trace)
 ```
 
 NOTE: **Note:**

ee/lib/gitlab/geo.rb

@@ -128,7 +128,7 @@ module Gitlab
     end
 
     def self.repository_verification_enabled?
-      Feature.enabled?('geo_repository_verification', default_enabled: true)
+      Feature.enabled?(:geo_repository_verification, default_enabled: true)
     end
 
     def self.allowed_ip?(ip)

lib/gitlab/ci/trace.rb

@@ -147,7 +147,7 @@ module Gitlab
             raise AlreadyArchivedError, 'Could not write to the archived trace'
           elsif current_path
             File.open(current_path, mode)
-          elsif Feature.enabled?('ci_enable_live_trace', job.project)
+          elsif Feature.enabled?(:ci_enable_live_trace, job.project)
             Gitlab::Ci::Trace::ChunkedIO.new(job)
           else
             File.open(ensure_path, mode)