Fix Issues with Missing Message and Incorrect Resource Name

I've identified several issues with the current protobuf files that need to be addressed:

- **Missing Message Definition**: In the `braking_service.proto` file, there is a `BrakeAssistance` publish topic, but the corresponding message definition is missing in its topics proto.
- **Incorrect Resource name**: In engine_service.proto, the publish topic is defined as:
`option (uprotocol.publish_topic) = {
id : 0x8001,
name : "horn",
message : "oil"
};`
This should be updated to:
`option (uprotocol.publish_topic) = {
id : 0x8001,
name : "oil",
message : "Oil"
};`

Inspect braking_service.proto and the associated topics proto to identify where the BrakeAssistance message is expected, then review engine_service.proto for the publish-topic declaration. Done means the missing message is defined in the appropriate topics proto and the engine topic uses name "oil" with message "Oil"; verify the protobuf files remain valid.

Written by the indexing model from the issue text.