bug(MatList): Icons do not respect RTL direction

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

When using MatList in an RTL project, the icons do not adjust their margins correctly based on the text direction (dir="rtl"). The left and right margins remain the same as in LTR mode, causing misalignment in RTL layouts.

I was able to fix this issue easily with custom CSS, but I wanted to report it as a bug in case it needs to be addressed in the library.

### Reproduction

StackBlitz link:
Steps to reproduce:
1.
2.

### Expected Behavior

Icons should switch their margins correctly when dir="rtl" is set.

### Actual Behavior

Icons remain aligned as if the project is LTR, leading to incorrect spacing.

### Environment

Angular: 18
Angular Material: 19.1.5
Browser: Latest version of Chrome
Operating System: Windows (running a Linux dev container on WSL)

Inizia riproducendo il problema della spaziatura dell’icona di MatList in un progetto Angular 18 usando Angular Material 19.1.5, con dir="rtl" e l’ultima versione di Chrome. Confronta i margini e l’allineamento dell’icona in RTL e LTR; l’issue è completata quando la spaziatura dell’icona segue correttamente la direzione del testo.

Scritto dal modello di indicizzazione a partire dal testo della issue.