[ios, macos] Make MGLMapView non opaque by default (#7859)

platform/ios/CHANGELOG.md

@@ -6,6 +6,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 
 * Fixed a build error in the static framework flavor of this SDK caused by a missing header. ([#7844](https://github.com/mapbox/mapbox-gl-native/pull/7844))
 * Fixed an issue causing MGLMapView’s `camera`’s `heading` to be set to a negative value, indicating an undefined heading, when the map view faces northwest. The heading is now wrapped to between zero and 360 degrees, for consistency with MGLMapView’s `direction` property. ([#7724](https://github.com/mapbox/mapbox-gl-native/pull/7724))
+* Fixed an issue causing MGLMapView flash of black. ([#7859](https://github.com/mapbox/mapbox-gl-native/pull/7859))
 
 ## 3.4.0
 

platform/ios/src/MGLMapView.mm

@@ -394,7 +394,7 @@ public:
     MGLinitializeRunLoop();
 
     _isTargetingInterfaceBuilder = NSProcessInfo.processInfo.mgl_isInterfaceBuilderDesignablesAgent;
-    _opaque = YES;
+    _opaque = NO;
 
     BOOL background = [UIApplication sharedApplication].applicationState == UIApplicationStateBackground;
     if (!background)