bug: grid breakpoints based on window causing grid to be wrong in modal

# Bug Report

**Ionic version:**

[ ] **4.x**
[x] **5.6.4**

**Current behavior:**
The grid sizing is relative to the screen size.

**Expected behavior:**
The grid sizing be relative to the modal size.

**Steps to reproduce:**
Use the code given to createa component, open a modal window with the given component, check in the console the calc is using 4 instead of 6.

**Related code:**

```










```

**Other information:**

**Ionic info:**

```
[WARN] Error loading @capacitor/core package.json: Error: Cannot find module '@capacitor/core/package'

Require stack:
- C:\Users\joao_\AppData\Roaming\npm\node_modules\@ionic\cli\lib\project\index.js
- C:\Users\joao_\AppData\Roaming\npm\node_modules\@ionic\cli\lib\index.js
- C:\Users\joao_\AppData\Roaming\npm\node_modules\@ionic\cli\index.js
- C:\Users\joao_\AppData\Roaming\npm\node_modules\@ionic\cli\bin\ionic

Ionic:

Ionic CLI : 6.12.4 (C:\Users\joao_\AppData\Roaming\npm\node_modules\@ionic\cli)
Ionic Framework : @ionic/angular 5.6.4
@angular-devkit/build-angular : 0.1100.7
@angular-devkit/schematics : 11.2.4
@angular/cli : 11.2.8
@ionic/angular-toolkit : 2.3.3

Capacitor:

Capacitor CLI : not installed
@capacitor/core : not installed

Utility:

cordova-res : not installed
native-run : not installed

System:

NodeJS : v14.15.4 (C:\Program Files\nodejs\node.exe)
npm : 6.14.10
OS : Windows 10
```