Whitelist voice_icon_keyboard_accessory as not found image

ios/chrome/app/startup/setup_debugging.mm

Index: ios/chrome/app/startup/setup_debugging.mm
diff --git a/ios/chrome/app/startup/setup_debugging.mm b/ios/chrome/app/startup/setup_debugging.mm
index 7410a46d0cbae0196c8699fd1e7b4a30252f9d22..24ae2994c10c216fc143373650be13465ce2db4c 100644
--- a/ios/chrome/app/startup/setup_debugging.mm
+++ b/ios/chrome/app/startup/setup_debugging.mm
@@ -31,6 +31,8 @@ void swizzleUIImageImageNamed() {
   // TODO(crbug.com/720338): Add missing images.
   [whiteList addObject:@"glif-mic-to-dots-large_37"];
   [whiteList addObject:@"glif-google-to-dots_28"];
+  // TODO(crbug.com/721338): Add missing image.
+  [whiteList addObject:@"voice_icon_keyboard_accessory"];
 
   // The original implementation of [UIImage imageNamed:].
   // Called by the new implementation.