Use a raw string to correctly print \n in option description in the analysis server.

pkg/analysis_server/lib/src/server/driver.dart

Index: pkg/analysis_server/lib/src/server/driver.dart
diff --git a/pkg/analysis_server/lib/src/server/driver.dart b/pkg/analysis_server/lib/src/server/driver.dart
index 62d875847a76fdf3f3838a56f56fc41842fa98dc..c332d237487b2f21bcef4be43aaef87f8ce70f4d 100644
--- a/pkg/analysis_server/lib/src/server/driver.dart
+++ b/pkg/analysis_server/lib/src/server/driver.dart
@@ -343,7 +343,7 @@ class Driver implements ServerStarter {
         allowedHelp: {
       "as-is": "file contents are read as-is, no file changes occur",
       "normalize-eol-always":
-          "file contents normalize the end of line characters to the single character new line `\n`"
+          r'file contents normalize the end of line characters to the single character new line `\n`'
     }, defaultsTo: "as-is");
 
     return parser;