Speed up loading banner animations

Summary:
This diff reduces the minimum loading banner time and animation time to make the locating banner faster.

Changelog: [General] [iOS] Speed up loading banner animations

Reviewed By: PeteTheHeat

Differential Revision: D21290517

fbshipit-source-id: 111dff41df53b0246548e1da1db80c2188498a9c

React/CoreModules/RCTDevLoadingView.mm

@@ -186,11 +186,11 @@ - (void)showMessage:(NSString *)message color:(UIColor *)color backgroundColor:(
 
   dispatch_async(dispatch_get_main_queue(), ^{
     self->_hiding = true;
-    const NSTimeInterval MIN_PRESENTED_TIME = 0.6;
+    const NSTimeInterval MIN_PRESENTED_TIME = 0.5;
     NSTimeInterval presentedTime = [[NSDate date] timeIntervalSinceDate:self->_showDate];
     NSTimeInterval delay = MAX(0, MIN_PRESENTED_TIME - presentedTime);
     CGRect windowFrame = self->_window.frame;
-    [UIView animateWithDuration:0.25
+    [UIView animateWithDuration:0.1
         delay:delay
         options:0
         animations:^{