Jenn Magder d4f698b036 Fix UIVisualEffectView leak in platform view filter (flutter/engine#52591)
I found this while migrating `FlutterPlatformViews_Internal.mm` to ARC https://github.com/flutter/engine/pull/52535.  I'll land this first.

```objc
  if (_backdropFilterView != visualEffectView) {
    _backdropFilterView = [visualEffectView retain];
  }
```
should instead be something like:
```objc
  if (_backdropFilterView != visualEffectView) {
    id oldBackdropFilterView = _backdropFilterView;
    _backdropFilterView = [visualEffectView retain];
    [oldBackdropFilterView release];
  }
```
But that's already what the built-in MRC `nonatomic, retain` property setter does, so use that instead.

Added a test that passes on this PR and fails on main.
2024-05-08 22:40:16 +00:00
..