fix: currentColor dimming (#2465)

# Summary

Fixes #2455. When the shared modal was triggered, the `currentColor`
(which is `tintColor` under the hood) was being greyscaled because the
default value of `tintAdjustmentMode` was set to
`UIViewTintAdjustmentModeDimmed`. Changing it to
`UIViewTintAdjustmentModeNormal` resolves the issue.

## Test Plan

Example apps -> `Test2455`

## Compatibility

| OS      | Implemented |
| ------- | :---------: |
| iOS     |    ✅      |

apple/Elements/RNSVGSvgView.mm

@@ -47,6 +47,8 @@ using namespace facebook::react;
     // This is necessary to ensure that [self setNeedsDisplay] actually triggers
     // a redraw when our parent transitions between hidden and visible.
     self.contentMode = UIViewContentModeRedraw;
+    // We don't want the dimming effect on tint as it's used as currentColor
+    self.tintAdjustmentMode = UIViewTintAdjustmentModeNormal;
 #endif // TARGET_OS_OSX
     rendered = false;
 #ifdef RCT_NEW_ARCH_ENABLED