Fixing document picker issue

Related to #110

Author: vishalnarkhede

README.md

@@ -75,6 +75,8 @@ The React Native components are created using the stream-chat-js library. If you
 1. Navigation between different component is something we expect consumers to
    implement. You can checkout the example given in this repository
 
+2. Minor releases may come with some breaking changes, so always check the release notes before upgrading minor version.
+
 Library currently exposes following components:
 
 1. Avatar

src/components/MessageInput.js

@@ -455,7 +455,7 @@ const MessageInput = withKeyboardContext(
               return;
 
             const result = await pickDocument();
-            if (result.type === 'cancel') {
+            if (result.type === 'cancel' || result.cancelled) {
               return;
             }
             const mimeType = lookup(result.name);