Fix for the UIKeyboardBounds deprecated warnings which are present in the default Unity-iOS Project files.

Keyboard.mm

// Original code as present in the source
CGPoint center = [[notification.userInfo objectForKey:UIKeyboardCenterEndUserInfoKey] CGPointValue];
CGRect  rect   = [[notification.userInfo objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue];

// Correct code to replace it
CGRect rect = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));