fix opacity issue on ios--using(using color box)

[venbrinoDev]

Fix issue on ios

opacity having issue on ios and it cause janky issue

i fixed by using color box

[emmanueljoshua1]

Guys please merge this PR.

[Adminixtrator]

hey @venbrinoDev @emmanueljoshua1,

you can just switch to LoadingOverlayPro, it basically has the same constructors as LoadingOverlay and you do not need any additional configurations like the other packages.

LoadingOverlayPro({
    Key key,
    @required this.isLoading,
    @required this.child,
    this.colorBackground = Colors.black54,
    this.progressIndicator = const LoadingBouncingLine.circle(),
  });

// only isLoading && child is required

goodluck, and goodspeed👍