Remove unnecessary kCliAnimationsFeatureName that is available as .configSetting. (#158013)

... for consistency with the rest of the file/features.

Author: matanlurey

packages/flutter_tools/lib/src/features.dart

@@ -146,14 +146,12 @@ const Feature flutterCustomDevicesFeature = Feature(
   ),
 );
 
-const String kCliAnimationsFeatureName = 'cli-animations';
-
 /// The [Feature] for CLI animations.
 ///
 /// The TERM environment variable set to "dumb" turns this off.
 const Feature cliAnimation = Feature.fullyEnabled(
   name: 'animations in the command line interface',
-  configSetting: kCliAnimationsFeatureName,
+  configSetting: 'cli-animations',
 );
 
 /// Enable native assets compilation and bundling.

packages/flutter_tools/test/general.shard/reporting/first_run_test.dart

@@ -20,7 +20,7 @@ void main() {
   testWithoutContext('FirstRunMessenger informs user how to disable animations', () {
     final FirstRunMessenger messenger = setUpFirstRunMessenger(redisplayWelcomeMessage: false);
 
-    expect(messenger.licenseTerms, contains('flutter config --no-$kCliAnimationsFeatureName'));
+    expect(messenger.licenseTerms, contains('flutter config --no-${cliAnimation.configSetting}'));
   });
 
   testWithoutContext('FirstRunMessenger requires redisplay if it has never been run before', () {