bug(MatChipList): matChipInputFor changes height of MatFormField (Chips Autocomplete)

#### Reproduction

https://material.angular.io/components/chips/examples

Steps to reproduce:
1. When `mat-form-field` is empty (no value is set) the height is 65.5px
2. When `mat-chip` is added height is 79.5px.

#### Expected Behavior

`mat-form-field` should not change its height.

#### Actual Behavior

`mat-form-field` changes its height when first value is added.

#### Environment

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

从 material.angular.io/components/chips/examples 中的 Chips Autocomplete 示例开始，重现空的 mat-form-field 与包含第一个 mat-chip 的 mat-form-field 之间的高度变化。跟踪 matChipInputFor 和 mat-form-field 的相关行为；完成标准是添加第一个 chip 后字段保持相同的高度。

由索引模型根据 Issue 内容生成。