Error in ng build --prod | Property is {} so missing.

### Issue in production build

- Error statement
1. **Property `'color'` does not exist on type `'{}'`.**
2. **Property `'d'` does not exist on type `'{}'`.**

* [x] bug report

### Issue description
- Angular `ng` not able to build with `prod` argument.

**Related code:**

In `temperature-dragger.component.ts` file
```typescript
styles = {
viewBox: '0 0 300 300',
arcTranslateStr: 'translate(0, 0)',
clipPathStr: '',
gradArcs: [],
nonSelectedArc: {},
thumbPosition: { x: 0, y: 0 },
blurRadius: 15,
};
```
It needs to be
```typescript
angle = this.bottomAngleRad / 2 + (1 - this.getValuePercentage()) * (2 * Math.PI - this.bottomAngleRad);
styles = {
viewBox: '0 0 300 300',
arcTranslateStr: 'translate(0, 0)',
clipPathStr: '',
gradArcs: [],
nonSelectedArc:{
color: this.disableArcColor,
d: `M ${this.radius},${this.radius}
L ${this.radius},${3 * this.radius}
A ${2 * this.radius},${2 * this.radius}
1 ${this.angle > Math.PI ? '1' : '0'} 0
${this.radius + this.radius * 2 * Math.sin(this.angle)},${this.radius + this.radius * 2 * Math.cos(this.angle)}
Z`,
},
thumbPosition: { x: 0, y: 0 },
blurRadius: 15,
};
```

### Other information:

Node, npm: `v12.13.0.` and `6.12.0`
OS: Windows (10)

**Angular, Nebular**