bug(style): Custom palette's text hue not propagated to MDC styles

### Is this a regression?

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

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

14.x

### Description

[Re-opening #26021 which was incorrectly closed as a duplicate of a similar but different issue]

[This is a regression insofar as the legacy non-MDC implementations do not have this problem]

Hi, after running the MDC schematic on one of my projects I have found that the MDC-based components do not use the `$text` hue specified in the theme config, which can cause accessibility issues for themes whose default hues do not provide sufficient contrast against a neutral background. In particular I have noticed this causes legibility issues for the floating placeholder on form fields and the label text on default-appearance buttons, but it might apply to other components as well.

My theme is configured as follows:

`$my-palette: mat.define-palette($greens, 600, 200, 900, 700);`
Note that the $text hue is overridden to `700` in the call to `define-palette`.

Here is a screenshot showing the 700 hue being correctly applied to the aforementioned text elements under the legacy components:


And here is how the new MDC components look:


I had a hard time reading the Angular Material => MDC SCSS theming code but it seems like the $text hue preference isn't being passed to the MDC mixins in any way.

### Reproduction

StackBlitz link:
Steps to reproduce:
1. https://stackblitz.com/edit/components-issue-9ugktp?file=src%2Fstyles.scss
2. Note that text hue is set to 900 but text button and form field label use 500

### Expected Behavior

MDC components should use specified text hue where applicable

### Actual Behavior

MDC components used primary hue regardless

### Environment

Environment
Angular: 15.0.0-18.0.1
CDK/Material: 15.0.0-18.0.1
Browser(s): Chrome
Operating System (e.g. Windows, macOS, Ubuntu): Windows 10

Start with src/styles.scss in the linked StackBlitz and trace the Angular Material MDC SCSS theming code around mat.define-palette and the MDC mixins. Compare the legacy and MDC output for the configured $text hue, then verify that applicable MDC text elements, including form-field labels and default buttons, use the specified hue in the reproduction.

Written by the indexing model from the issue text.