Unsupported UI RPCs take a long time to respond

[joeljfischer]

Bug Report

When sending a ScrollableMessage RPC, it takes a very long time for the generic_hmi to respond. It should respond with an error almost immediately.

Reproduction Steps

1. Connect
2. Send ScrollableMessage

Expected Behavior

An error response returns in < 1 second

Observed Behavior

An error response returns in ~30 seconds

Browser & Version Information

• Browser and Version: Manticore (Safari 15.1)
• RPC Sent: ScrollableMessage
• Output Received: n/a
• Generic HMI Version: 0.10.0
• Testing Against: Manticore

Test Case, Sample Code, and / or Example App

n/a