aws_codecommit: initial repository code does not retain file permission mode

### Describe the bug

[CodeCommit repository](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_codecommit.Repository.html) has a construct prop `code` that should include the initial code of repository. I am using Java CDK `Code.fromDirectory` to create the code object.

My local files are executable (permission 755). The files finally in the CodeCommit repository are not executable (permission 644).

### Expected Behavior

The files uploaded to CodeCommit should remain their file permission mode.

### Current Behavior

Local executable files, when uploaded to CodeCommit repository, do not have the execution bit set in their permission mode.

### Reproduction Steps

Using Java CDK:
```
Repository repository = Repository.Builder.create(this, "Repository")
.code(Code.fromDirectory("./revisions/codesuite"))
.build();
```
Put some files in the `./revisions/codesuite` folder.
Then run `chmod a+x ./revisions/codesuite/*`

Create the stack.

Use `git clone` to download the files from the CodeCommit repository.

Use `ls -la` to check the file permission mode.

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### CDK CLI Version

2.62.2 (build c164a49)

### Framework Version

_No response_

### Node.js Version

v14.17.0

### OS

Mac

### Language

Java

### Language Version

OpenJDK Runtime Environment Corretto-8.362.08.1 (build 1.8.0_362-b08)

### Other information

_No response_

Start with the aws_codecommit Repository construct and the Code.fromDirectory path described in the reproduction, then reproduce the behavior with an executable local file and inspect the resulting CodeCommit checkout using ls -la. Done means files uploaded through the code prop retain their local executable permission mode.

Written by the indexing model from the issue text.