Fix Writing Large files to containerd content store

it looks like the write failed when saving the new content. Will need to implement streaming for larger content when doing the write. Right now it writes and commits in one action:

runwasi/crates/containerd-shim-wasm/src/sandbox/containerd/client.rs

Lines 198 to 201 in 2171b3d

    
           // Write and commit at same time 
        
           let mut labels = HashMap::new(); 
        
           labels.insert(label.to_string(), original_digest.clone()); 
        
           let commit_request = WriteContentRequest {

Originally posted by @jsturtevant in #492 (comment)

	// Write and commit at same time
	let mut labels = HashMap::new();
	labels.insert(label.to_string(), original_digest.clone());
	let commit_request = WriteContentRequest {