bug(mdc-card): Negative margin on subtitle

### 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

The card subtitle has a negative margin, causing it to run into the card title

### Reproduction

https://stackblitz.com/edit/angular-wro35c-pjrlt2?file=src%2Fapp%2Fcard-subtitle-example.html

### Expected Behavior

Should look more spaced

### Actual Behavior

Shouldnt run into each other

### Environment

- Angular:
- CDK/Material:
- Browser(s):
- Operating System (e.g. Windows, macOS, Ubuntu):

Start with the linked StackBlitz reproduction, especially src/app/card-subtitle-example.html, and verify the subtitle and title overlap. Trace the Angular Material MDC card subtitle styling that produces the negative margin. Done means the subtitle has visible spacing from the title and the reproduction no longer shows them running into each other.

Written by the indexing model from the issue text.