Inconsistent behavior between OutputBinding<String> and OutputBinding<List<String>>

The following code results in 2 rows in the cosmos DB

```Java
@FunctionName("CosmosDBTriggerJava1")
public void run(
@CosmosDBTrigger(
name = "items",
databaseName = "db1",
collectionName = "col3",
leaseCollectionName="leases",
connectionStringSetting = "juzhucos_DOCUMENTDB",
createLeaseCollectionIfNotExists = true
)
Object[] items,
@CosmosDBOutput(name = "database",
databaseName = "db1",
collectionName = "col2",
connectionStringSetting = "juzhucos_DOCUMENTDB")
OutputBinding outputItem, //this line caused error. It works with OutputBinding> and OutputBinding
final ExecutionContext context
) {
outputItem.setValue("[{\"name\":\"value 0\"},{\"name\":\"value 1\"}]");
}

```

While the following code results in error

```Java
@FunctionName("CosmosDBTriggerJava")
public void run(
@CosmosDBTrigger(
name = "items",
databaseName = "db1",
collectionName = "col1",
leaseCollectionName="leases",
connectionStringSetting = "juzhucos_DOCUMENTDB",
createLeaseCollectionIfNotExists = true
)
Object[] input,
@CosmosDBOutput(name = "database",
databaseName = "db1",
collectionName = "col2",
connectionStringSetting = "juzhucos_DOCUMENTDB")
OutputBinding> outputItem,
final ExecutionContext context
) {
List items = new ArrayList();

for (int i = 0; i < 2; i ++) {
items.add("{\"name\":\"value 0\"}");
}

outputItem.setValue(items);
}

```

```
[1/19/2020 8:47:13 AM] Executed 'Functions.CosmosDBTriggerJava' (Failed, Id=8e0edee5-49f5-4afc-82ff-fde57a43b67b)
[1/19/2020 8:47:13 AM] System.Private.CoreLib: Exception while executing function: Functions.CosmosDBTriggerJava. Microsoft.Azure.DocumentDB.Core: Value cannot be null.
[1/19/2020 8:47:13 AM] Parameter name: document.
```

This is because the first one is serialized to an array of 2 JSON objects, when doing RPC from the Java worker to the function host.
```Java
[{"name":"value 0"},{"name":"value 1"}]
```
While the later one is serialized to an array of 2 strings
```Java
["{\"name\":\"value 0\"}","{\"name\":\"value 1\"}"]
```

Can we make the later one support adding JSON string objects to the list, since the first one supports that.