[Android][expo-filesystem] Fix FileSystem.downloadAsync throwing Null…

…PointerException

* add null safe check in FileSystem#downloadAsync java implementation

fix #6818

* document fix in changelog

CHANGELOG.md

@@ -23,6 +23,7 @@ This is the log of notable changes to the Expo client that are developer-facing.
 - Fixed fullscreen events on iOS for native controls. ([#6504](https://github.com/expo/expo/pull/6504) by [@mczernek](https://github.com/mczernek))
 - Fixed `Camera.takePictureAsync()` not saving metadata on iOS. ([#6428](https://github.com/expo/expo/pull/6428) by [@lukmccall](https://github.com/lukmccall))
 - Fixed `KeyboardAvoidingView` in standalone Android builds. ([#6506](https://github.com/expo/expo/pull/6506) [@bbarthec](https://github.com/bbarthec))
+- Fixed `FileSystem.downloadAsync()` throwing `NullPointerException` in rare failures on Android. ([#6819](https://github.com/expo/expo/pull/6819) by [@jsamr](https://github.com/jsamr/))
 
 ## 36.0.0
 

packages/expo-file-system/android/src/main/java/expo/modules/filesystem/FileSystemModule.java

@@ -499,7 +499,7 @@ public void downloadAsync(String url, final String uriStr, final Map<String, Obj
         getOkHttpClient().newCall(requestBuilder.build()).enqueue(new Callback() {
           @Override
           public void onFailure(Call call, IOException e) {
-            Log.e(TAG, e.getMessage());
+            Log.e(TAG, String.valueOf(e.getMessage()));
             promise.reject(e);
           }