Update 'request changes' icon (#2694)

Author: viktorasl

Classes/Issues/Review/IssueReviewDetailsCell.swift

@@ -83,7 +83,7 @@ final class IssueReviewDetailsCell: IssueCommentBaseCell, ListBindable {
             action = NSLocalizedString("requested changes", comment: "")
             iconBackgroundColor = Styles.Colors.Red.medium.color
             iconTintColor = .white
-            iconName = "x-small"
+            iconName = "request-changes"
         case .approved:
             action = NSLocalizedString("approved", comment: "")
             iconBackgroundColor = Styles.Colors.Green.medium.color

Resources/Assets.xcassets/request-changes.imageset/Contents.json

@@ -0,0 +1,12 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "request-changes.pdf"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}