Generalize ActionSheetManager items URL

Summary:
Not ready but want to start conversation.  (i.e. not sure if to change key name to `urls` from `url`)

I want to be able to share more than 1 image at a time, the current code only lets one use one url, but the API allows for much more.

Some places already make this an issue:

react-native-share/react-native-share#85

And I also need to be able to email/send on iMessage, etc with multiple URL resources.
Closes #15475

Differential Revision: D6437807

Pulled By: hramos

fbshipit-source-id: 336c696c5633c0080904ca9306a38120e27f9173

Libraries/ActionSheetIOS/RCTActionSheetManager.m

@@ -133,11 +133,17 @@ - (CGRect)sourceRectInView:(UIView *)sourceView
   if (message) {
     [items addObject:message];
   }
-  NSURL *URL = [RCTConvert NSURL:options[@"url"]];
-  if (URL) {
-    if ([URL.scheme.lowercaseString isEqualToString:@"data"]) {
+  NSArray<NSURL *> *URLS = [RCTConvert NSURLArray:options[@"url"]];
+
+  if (URLS.count == 0) {
+    RCTLogError(@"No `url` or `message` to share");
+    return;
+  }
+
+  for (NSURL *url in URLS) {
+    if ([url.scheme.lowercaseString isEqualToString:@"data"]) {
       NSError *error;
-      NSData *data = [NSData dataWithContentsOfURL:URL
+      NSData *data = [NSData dataWithContentsOfURL:url
                                            options:(NSDataReadingOptions)0
                                              error:&error];
       if (!data) {
@@ -146,13 +152,9 @@ - (CGRect)sourceRectInView:(UIView *)sourceView
       }
       [items addObject:data];
     } else {
-      [items addObject:URL];
+      [items addObject:url];
     }
   }
-  if (items.count == 0) {
-    RCTLogError(@"No `url` or `message` to share");
-    return;
-  }
 
   UIActivityViewController *shareController = [[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];