CameraViewportState initial position is jumping

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When initially loading a map that uses `CameraViewportState`, the map is briefly centering to a different center than configured.
This behavior is different to when using `CameraOptions`, where the `onCameraChangeListener` is also fired twice, but both with the same center.

```
MapWidget(
key: ValueKey("mapWidget"),
viewport: CameraViewportState(
center: Point(coordinates: Position(-117.918976, 33.812092)),
bearing: currentCity.bearing,
pitch: 0,
zoom: 18),
onCameraChangeListener: (cameraChangedEventData) =>
print(cameraChangedEventData.cameraState.center.toJson()),
),
```

Output for `onCameraChangeListener`:
```
{type: Point, bbox: null, coordinates: [-9.999999999999972, 29.999999999999964]}
{type: Point, bbox: null, coordinates: [-117.918976, 33.812092000000014]}
```

When configuring both, `viewport ` and `cameraOptions`, it first centers to the position from `cameraOptions` and then to the position of `viewport`. Maybe there is some unwanted default/calculation when using `viewport` alone?

```
MapWidget(
key: ValueKey("mapWidget"),
viewport: CameraViewportState(
center: Point(coordinates: Position(-117.918976, 33.812092)),
bearing: currentCity.bearing,
pitch: 0,
zoom: 18),
cameraOptions: CameraOptions(
center: Point(coordinates: Position(-100.918976, 33.812092)),
zoom: 18,
),
onCameraChangeListener: (cameraChangedEventData) =>
print(cameraChangedEventData.cameraState.center.toJson()),
),
```
Output for `onCameraChangeListener`:
```
{type: Point, bbox: null, coordinates: [-100.918976, 33.812092000000035]}
{type: Point, bbox: null, coordinates: [-117.918976, 33.812092000000014]}
```

Start by reproducing the initial load with MapWidget using CameraViewportState and onCameraChangeListener, then compare it with CameraOptions and the combined configuration shown in the report. Done means the initial camera does not briefly jump to an unintended center and the reported camera-change events have consistent centers.

Written by the indexing model from the issue text.