polkadot.js api not receiving messages from chain.subscribeFinalizedHeads

[edwardmack]

Expected Behavior

• polkadot.js api rpc.chain.subscribeFinalizedHeads should get message when a block is finalized.

Current Behavior

• No response is received from polkadot.js api rpc.chain.subscribeFinalizedHeads when a block is finalized.

Possible Solution

• Related to Polkadot.js Integration #790

Steps to Reproduce

1. example call:

...
 await api.rpc.chain.subscribeFinalizedHeads((lastFin) => {
                console.log(`${chain}: last finalized block #${lastFin.number} has hash ${lastFin.hash}`)       
});
...

Specification

• go version:
• gossamer version:
• gossamer commit tag:
• gossamer commit hash:
• operating system:
• additional links:

Checklist

• I have read CODE_OF_CONDUCT and CONTRIBUTING
• I have provided as much information as possible and necessary
• I am planning to submit a pull request to fix this issue myself