This patch improves the error handling for when a user tries to add
a parameter which is either an alias of a existing parameter, the
primary name of a existing aliased parameter, or a name/alias of an
existing parameter which is shown with an override label.
The error message was modified to always refer to the conflicting
parameter using the same name that is has in the sidebar.
Example: A parameter named "Parameter B" is already present in the
sidebar under its alias "B". When a user tries to add "Parameter B",
the new error message will inform the user that the parameter they
are trying to add already exists as "B".
Bug: T285869
Change-Id: I762b72b6cf14eb8ff5fcef63b4dcb70e297050de
This is split from patch Iebb982e to make it easier to review.
The name is rather ambiguous. Does "input" refer to the input
element? Is it triggered for every key press, i.e. when the
input changes? Or when it's submitted?
Change-Id: Iddbe3bfb9faf3561d8d71b96ffae507799827a95
