nb-install-component() does not work if component is around ng-template.

### Issue type

**I'm submitting a ...** (check one with "x")

* [x] bug report
* [ ] feature request

### Issue description

**Current behavior:**

If component is surrounded by ng-template, classes defined under nb-install-component() is simply ignored.

**Expected behavior:**

If I inject a template and create an embedded view, everything under nb-install-component() mixin is ignored.

**Steps to reproduce:**

Create a component and use template injection.

Why do I need template injection? Here is the history: https://stackoverflow.com/questions/59505387/angular-bootstrap-grid-component

**Related code:**

```

$

```

Sample project at Stackblitz: https://stackblitz.com/github/jvminzkz

### Other information:

**npm, node, OS, Browser**
```
Node version: v12.14.0
OS: Windows 10
Browser: Chrome 80.0.3987.163
```

**Angular, Nebular**
```
Angular 9.04
Nebular 5.0
```