[vm-service] - Fix location in which the vm-service server looks for the dds snapshot.

The location of the dds snapshot was changed when the g3 roll failed and at that time this code was not changed accordingly.

TEST=ci and manual testing

Change-Id: I92b43f68b082d7c2c7a7e56f53ccb987cbfb72e7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/414382
Reviewed-by: Alexander Aprelev <[email protected]>
Commit-Queue: Siva Annamalai <[email protected]>

Author: a-siva

sdk/lib/_internal/vm/bin/vmservice_server.dart

@@ -165,11 +165,7 @@ class _DebuggingSession {
       'dds_aot.dart.snapshot',
     ].join(Platform.pathSeparator);
     if (FileSystemEntity.typeSync(script) == FileSystemEntityType.notFound) {
-      script = [
-        dartDir,
-        'gen',
-        'dds_aot.dart.snapshot',
-      ].join(Platform.pathSeparator);
+      script = [dartDir, 'dds_aot.dart.snapshot'].join(Platform.pathSeparator);
       if (FileSystemEntity.typeSync(script) == FileSystemEntityType.notFound) {
         executable = [dartDir, dart].join(Platform.pathSeparator);
         script = 'development-service';