Whitespaces are not trimmed in Text Node with `preserveWhitespaces: false`

# 🐞 bug report

### Affected Package

The issue is caused by package `@angular/compiler`

### Is this a regression?

Yes, the previous version in which this bug was not present was: ....

No idea

### Description

A clear and concise description of the problem...

https://github.com/angular/angular/blob/d1ea1f4c7f3358b730b0d94e65b00bc28cae279c/packages/compiler/src/ml_parser/html_whitespaces.ts#L78

```html

{{ 'text' }}

{{ 'text' }}

{{ 'text' }}
```

There is no way to `trim` the text.

## 🔬 Minimal Reproduction

https://stackblitz.com/edit/angular-ivy-pkkssb

## 🌍 Your Environment

**Angular Version:**

Angular CLI: 9.1.1

Node: 12.18.0

OS: darwin x64

Angular: 9.1.2

... animations, common, compiler, compiler-cli, core, forms

... platform-browser, platform-browser-dynamic, router

Ivy Workspace: Yes

Package                           Version

-----------------------------------------------------------

@angular-devkit/architect         0.901.1

@angular-devkit/build-angular     0.901.1

@angular-devkit/build-optimizer   0.901.1

@angular-devkit/build-webpack     0.901.1

@angular-devkit/core              9.1.1

@angular-devkit/schematics        9.1.1

@angular/cdk                      9.2.1

@angular/cli                      9.1.1

@angular/flex-layout              9.0.0-beta.29

@ngtools/webpack                  9.1.1

@schematics/angular               9.1.1

@schematics/update                0.901.1

rxjs                              6.5.5

typescript                        3.8.3

webpack                           4.42.0

**Anything else relevant?**

Start with packages/compiler/src/ml_parser/html_whitespaces.ts at the referenced line and reproduce the behavior using the linked StackBlitz example. Trace how whitespace is handled for text nodes when preserveWhitespaces is false, then verify that the sample input produces the expected span without surrounding spaces.

Written by the indexing model from the issue text.