Need API Setting to allow modify kubelet config for Json logging format

**What I'd like:**
We would like to have an option to modify kubelet logging format changed using toml setting. It would be nice if we can offer more kubelet config setting via API.

**Any alternatives you've considered:**
If we modify `/etc/kubernetes/kubelet/config` by appending logging format setting works by SSH/SSM to the bottler rocket instance, however currently there is no toml setting which allows the same : https://bottlerocket.dev/en/os/1.19.x/api/settings/kubernetes/
```
cat << 'EOF' >> /etc/kubernetes/kubelet/config
logging:
format: json
EOF
```

I tried updating `/etc/kubernetes/kubelet/config` to setup kubelet logging to json format using bootstrap-containers. However, its failing with Permission denied .
Here is my setup :

Dockerfile
```
FROM alpine
ADD bootstrap-script /
RUN chmod +x /bootstrap-script
ENTRYPOINT ["./bootstrap-script"]
```
bootstrap-script:
```
#!/bin/sh
# We'll update kubelet logging setting to json formating
set -ex

# Write output to stderr so it shows up in the journal.
exec 2>&1

# Test create a file
HOST_VAR_DIR=/.bottlerocket/rootfs/var
touch $HOST_VAR_DIR/hello_world

echo "starting bootstrap container"
USER_DATA_DIR=/.bottlerocket/bootstrap-containers/current

# This is the in-container view of where the host's `/var` can be accessed.
HOST_DIR=/.bottlerocket/rootfs

# The directory that'll be created by this bootstrap container
MY_HOST_DIR=$HOST_DIR/etc/kubernetes/kubelet

# Create it!
echo "creating folder"
id
ls -la $MY_HOST_DIR

echo -e "logging:\n format: json" >> $MY_HOST_DIR/config
# touch $MY_HOST_DIR/hello-world-1
```

Extra args in toml user-data (in-addition to your other args to join cluster)
```
[settings.host-containers.admin]
"enabled" = true
[settings.bootstrap-containers.kubeletlogging]
source="/bottlerocket-kubelet-change:latest"
mode="once"
user-data="bG9nZ2luZzoKICBmb3JtYXQ6IGpzb24K"
```

Error:
```
./bootstrap-script: line 29: can't create /.bottlerocket/rootfs/etc/kubernetes/kubelet/config: Permission denied
```

Its understood that, Bootstrap containers aren’t allowed to write to /etc. The content there is ephemeral and needs to be managed by the host. Bottlerocket will need to add a setting to the API to enable this.