Readded Delete Message Button for own user and outBox, and ensured delete message is avaliable for all roles above admin

Author: KshitizSareen

src/action-sheets/index.js

@@ -692,6 +692,7 @@ export const constructMessageActionButtons = (args: {|
 |}): Button<MessageArgs>[] => {
   const { backgroundData, message, narrow, canStartQuoteAndReply } = args;
   const { ownUser, flags } = backgroundData;
+  const { role } = ownUser;
   const buttons = [];
 
   if (message.isOutbox === true) {
@@ -730,6 +731,9 @@ export const constructMessageActionButtons = (args: {|
     // TODO(#2793): Don't show if message isn't deletable.
     buttons.push(deleteMessage);
   }
+  if (roleIsAtLeast(role, Role.Admin) && messageNotDeleted(message)) {
+    buttons.push(deleteMessage);
+  }
   if (
     // When do we offer "Mark as unread from here"?  This logic parallels
     // `should_display_mark_as_unread` in web's static/js/popovers.js .

src/chat/ChatScreen.js

@@ -164,7 +164,7 @@ export default function ChatScreen(props: Props): Node {
           () => undefined,
         );
 
-        if ((content !== undefined && content !== '') || (topic !== undefined && topic !== '')) {
+        if (content !== undefined || topic !== undefined) {
           api.updateMessage(auth, editMessage.id, { content, subject: topic }).catch(error => {
             showErrorAlert(_('Failed to edit message'), error.message);
           });

src/compose/ComposeBox.js

@@ -521,7 +521,7 @@ const ComposeBox: React$AbstractComponent<Props, ImperativeHandle> = forwardRef(
       result.push('mandatory-topic-empty');
     }
 
-    if (messageInputValue.trim().length === 0) {
+    if (messageInputValue.trim().length === 0 && !isEditing) {
       result.push('message-empty');
     }
 
@@ -540,6 +540,7 @@ const ComposeBox: React$AbstractComponent<Props, ImperativeHandle> = forwardRef(
     numUploading,
     anyQuoteAndReplyInProgress,
     messageInputState,
+    isEditing,
   ]);
 
   const submitButtonDisabled = validationErrors.length > 0;