Show all mailto: handlers, but dim unavailable ones.

ios/chrome/browser/web/mailto_url_rewriter.mm

Index: ios/chrome/browser/web/mailto_url_rewriter.mm
diff --git a/ios/chrome/browser/web/mailto_url_rewriter.mm b/ios/chrome/browser/web/mailto_url_rewriter.mm
index 5bb6b26f089792357cd5cd9970c096d2100420f4..e264b91c5f4573e0f67f54d340a2a5180f2ffd32 100644
--- a/ios/chrome/browser/web/mailto_url_rewriter.mm
+++ b/ios/chrome/browser/web/mailto_url_rewriter.mm
@@ -113,7 +113,7 @@ NSString* const kMailtoDefaultHandlerKey = @"MailtoHandlerDefault";
   NSString* value = [self defaultHandlerID];
   if ([value length]) {
     MailtoHandler* handler = _handlers[value];
-    if (handler) {
+    if ([handler isAvailable]) {
       return [handler rewriteMailtoURL:gURL];
     }
   }
@@ -129,8 +129,7 @@ NSString* const kMailtoDefaultHandlerKey = @"MailtoHandlerDefault";
 
 - (void)addMailtoApps:(NSArray<MailtoHandler*>*)handlerApps {
   for (MailtoHandler* app in handlerApps) {
-    if ([app isAvailable])
-      [_handlers setObject:app forKey:[app appStoreID]];
+    [_handlers setObject:app forKey:[app appStoreID]];
   }
   [self migrateLegacyOptions];
   [self autoDefaultToGmailIfInstalled];