Update on "[BE] Remind users to update submodule"

Summary: 

Fixing #7243

As titled. This PR adds 2 things:
1. `check_and_update_submodule()` check if required submodule folders exist and at least contains a CMakeLists.txt file.
2. Give useful error when the submodule is corrupted (most likely missing a file, caused by submodule out of sync).

Test Plan: 

1. Test if we can still install, if submodule is not updated

```
rm -rf third-party/prelude
./install_executorch.sh
```
See the following log

```
...
Processing /data/users/larryliu/executorch
  Preparing metadata (pyproject.toml): started
  Running command Preparing metadata (pyproject.toml)
  2025-02-05 11:28:46,430 [ExecuTorch] WARNING: Some required submodules are missing. Updating submodules...
  Submodule path 'third-party/prelude': checked out '851d3f09c452937fc5adef27e2c50f7f304f1646'
  2025-02-05 11:28:46,748 [ExecuTorch] INFO: All required submodules are present.
  2025-02-05 11:28:47,018 [ExecuTorch] INFO: running dist_info
...
```
This proves that we can update submodule for the user.

2. Test if we can give useful error message, if we are missing a file.

```
rm third-party/gflags/src/gflags.cc
./install_executorch.sh --clean
./install_executorch.sh
```

See the following error:

```
  2025-02-05 12:08:56,889 [ExecuTorch] ERROR: Failed to query buck for sources. Failed command:

     buck2 cquery inputs(deps('//runtime/executor:program'))

  This is likely due to missing git submodules or outdated CMake cache. Please run the following before retry:

      ./install_executorch.sh --clean
      git submodule update --init --recursive

```
Reviewers:

Subscribers:

Tasks:

Tags:

Differential Revision: [D69156975](https://our.internmc.facebook.com/intern/diff/D69156975)

[ghstack-poisoned]

Author: larryliu0820

setup.py

@@ -59,7 +59,6 @@
 import subprocess
 
 from distutils import log
-from distutils.errors import DistutilsExecError
 from distutils.sysconfig import get_python_lib
 from pathlib import Path
 from typing import List, Optional
@@ -140,9 +139,8 @@ def check_folder(folder: str, file: str) -> bool:
     if missing_submodules:
         logger.warning("Some required submodules are missing. Updating submodules...")
         try:
-            subprocess.check_call(
-                ["git", "submodule", "update", "--init", "--recursive"]
-            )
+            subprocess.check_call(["git", "submodule", "sync"])
+            subprocess.check_call(["git", "submodule", "update", "--init"])
         except subprocess.CalledProcessError as e:
             logger.error(f"Error updating submodules: {e}")
             exit(1)
@@ -151,7 +149,7 @@ def check_folder(folder: str, file: str) -> bool:
         for path, file in missing_submodules.items():
             if not check_folder(path, file):
                 logger.error(f"{file} not found in {path}.")
-                logger.error("Please run `git submodule update --init --recursive`.")
+                logger.error("Please run `git submodule update --init`.")
                 exit(1)
     logger.info("All required submodules are present.")