[analysis_server] Use fixDataYamlFolder constant instead of string literals

Follow-up from https://dart-review.googlesource.com/c/sdk/+/296801.

Change-Id: I72ea8a42ec64c4bd6c6cee021a1464167ec368e6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/296862
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/context_manager.dart

diff --git a/pkg/analysis_server/lib/src/context_manager.dart b/pkg/analysis_server/lib/src/context_manager.dart
index 0cd05be..99ae940 100644
--- a/pkg/analysis_server/lib/src/context_manager.dart
+++ b/pkg/analysis_server/lib/src/context_manager.dart
@@ -458,7 +458,7 @@
         // packageName/lib/fix_data.yaml
         packageName = pathSegments[pathSegments.length - 3];
       } else {
-        var fixDataIndex = pathSegments.indexOf('fix_data');
+        var fixDataIndex = pathSegments.indexOf(file_paths.fixDataYamlFolder);
         if (fixDataIndex >= 2) {
           // packageName/lib/fix_data/foo/bar/fix.yaml
           packageName = pathSegments[fixDataIndex - 2];
@@ -574,7 +574,7 @@
 
           var fixDataFolder = rootFolder
               .getChildAssumingFolder('lib')
-              .getChildAssumingFolder('fix_data');
+              .getChildAssumingFolder(file_paths.fixDataYamlFolder);
           if (fixDataFolder.exists) {
             _analyzeFixDataFolder(driver, fixDataFolder, packageName);
           }

pkg/analyzer/lib/src/util/file_paths.dart

diff --git a/pkg/analyzer/lib/src/util/file_paths.dart b/pkg/analyzer/lib/src/util/file_paths.dart
index 8401087..bdfcd47 100644
--- a/pkg/analyzer/lib/src/util/file_paths.dart
+++ b/pkg/analyzer/lib/src/util/file_paths.dart
@@ -72,7 +72,7 @@
 /// Such files specify data-driven fixes.
 bool isFixDataYaml(p.Context pathContext, String path) {
   return pathContext.basename(path) == fixDataYaml ||
-      (pathContext.split(path).contains('fix_data') &&
+      (pathContext.split(path).contains(fixDataYamlFolder) &&
           pathContext.extension(path) == '.yaml');
 }