[SDL 0250] Next RPC Indication for the HMI

[theresalech]

Proposal: Next RPC Indication for the HMI

In situations with driver distraction, also with making a good UI, it really hurts the possible UX when the HMI has no idea what's going to happen next after the user taps an in-app menu item, a softbutton or a selection in a perform interaction.
This feature would provide apps with a way for the HMI to know what's next when a button or choice is selected.

This can be used in tandem with Template Improvements: Additional SubMenus to provide a fantastic user experience.

Review: smartdevicelink/sdl_evolution#827

Steering Committee Decision:

The Steering Committee voted to accept this proposal with revisions. The author will revise the proposal to specify that the HMI API doesn't use function IDs so SDL Core would communicate the next function ID through the existing RPC interface strings in the format of interfaceName.RPCMessage.
The proposal .md file was updated to reflect these revisions on 1/28/2020.