add __lldb_ prefix in test

Author: eronnen

lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py

@@ -1207,7 +1207,7 @@ def request_moduleSymbols(
         count: int = 0,
     ):
         command_dict = {
-            "command": "moduleSymbols",
+            "command": "__lldb_moduleSymbols",
             "type": "request",
             "arguments": {
                 "moduleId": moduleId,