new icon assets per design

Signal/Images.xcassets/album_add_more.imageset/Contents.json

@@ -2,17 +2,17 @@
   "images" : [
     {
       "idiom" : "universal",
-      "filename" : "album_add_more@1x.png",
+      "filename" : "add-photo-24@1x.png",
       "scale" : "1x"
     },
     {
       "idiom" : "universal",
-      "filename" : "album_add_more@2x.png",
+      "filename" : "add-photo-24@2x.png",
       "scale" : "2x"
     },
     {
       "idiom" : "universal",
-      "filename" : "album_add_more@3x.png",
+      "filename" : "add-photo-24@3x.png",
       "scale" : "3x"
     }
   ],

SignalMessaging/ViewControllers/AttachmentApprovalViewController.swift

@@ -1419,7 +1419,9 @@ class MediaMessageTextToolbar: UIView, UITextViewDelegate {
         textView.textContainerInset = UIEdgeInsets(top: 7, left: 7, bottom: 7, right: 7)
         textView.scrollIndicatorInsets = UIEdgeInsets(top: 5, left: 0, bottom: 5, right: 3)
 
-        addMoreButton.setImage(UIImage(named: "album_add_more"), for: .normal)
+        let addMoreIcon = #imageLiteral(resourceName: "album_add_more").withRenderingMode(.alwaysTemplate)
+        addMoreButton.setImage(addMoreIcon, for: .normal)
+        addMoreButton.tintColor = Theme.darkThemePrimaryColor
         addMoreButton.addTarget(self, action: #selector(didTapAddMore), for: .touchUpInside)
 
         let sendTitle = NSLocalizedString("ATTACHMENT_APPROVAL_SEND_BUTTON", comment: "Label for 'send' button in the 'attachment approval' dialog.")