Dropdown: when using selectedItem template if the selected option is 0 then no template is rendered

[frabonomi]

Describe the bug

When using the p-dropdown component with a custom selectedItem template to customize the selected label display as per documentation, the template isn't rendered if the selected option equals to 0.

From a quick look at the code it seems that this is happening because of the condition selectedItemTemplate && selectedOption. In my case the selectedOption is 0 and is therefore considered falsy, but it should be a treated as a possible valid value.

In a way it seems to be related to issue #14954

Environment

MacOS 14.2.1

Reproducer

https://stackblitz.com/edit/github-41pgth?file=src%2Fapp%2Fapp.component.html

Angular version

17.3.5

PrimeNG version

17.14.1

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

LTS

Browser(s)

No response

Steps to reproduce the behavior

1. Add a p-dropdown component
2. Set its options to an array containing a value that is 0
3. Define a custom selectedItem template
4. Select the option with the value 0

Expected behavior

The custom template should be rendered even if the selected option is 0.

[frabonomi]

Happy to open a PR for this, if needed ☝️

[frabonomi]

I think the main use case for this is when the options values are coming from an enum (without an initializer):

enum Direction {
  Up, // === 0
  Down,
  Left,
  Right,
}