Generate the code repeatedly in new java file

[v-yuyul]

Environment

• Operating System: Mac
• JDK version: 17.0.6
• Visual Studio Code version: 1.75.1
• Java extension version: 1.15.0

Steps To Reproduce

1. Open a java project, like https://github.com/redhat-developer/vscode-java/tree/master/test/resources/projects/eclipse/simple-app
2. Type the code File f = new File("demo.txt"); in a main method > Code Actions > Select Create class xxx, or Create interface xxx, or Create enum xxx

Current Result

Show the code repeatedly in the new java file.

Expected Result

Only show the code one time

[fbricon]

The bug already exists in 1.14

[fbricon]

Probably relates to #2938

[testforstephen]

It seems all file creation related refactorings probably have this issue.

For example, it can also be reproduced with "extract interface". The reason is that the client file event listener will inject duplicated snippet when the file is created by a WorkspaceEdit.

#2938 is a different bug, where the server side searching code generated duplicated results.