Java Question error: try-with-resources is not supported in -source 1.6 (INLINE JAVA)

public static class StickerContentProvider extends ContentProvider

    private synchronized void readContentFile(@NonNull Context context) {
        try (InputStream contentsInputStream = context.getAssets().open(CONTENT_FILE_NAME)) {
            stickerPackList = ContentFileParser.parseStickerPacks(contentsInputStream);
        } catch (IOException | IllegalStateException e) {
            throw new RuntimeException(CONTENT_FILE_NAME + " file has some issues: " + e.getMessage(), e);
        }
    }

public static final String CONTENT_FILE_NAME = "contents.json";

    private synchronized void readContentFile(@NonNull Context context) {
        InputStream contentsInputStream = GetIS("AssetsDir","contents.json");
        stickerPackList = ContentFileParser.parseStickerPacks(contentsInputStream);
        //try (InputStream contentsInputStream = GetIS("AssetsDir","contents.json")) {
        //    stickerPackList = ContentFileParser.parseStickerPacks(contentsInputStream);
        //} catch (IOException | IllegalStateException e) {
        //    throw new RuntimeException(CONTENT_FILE_NAME + " file has some issues: " + e.getMessage(), e);
        //}

    }
    public InputStream GetIS(String Dir, String File) throws IOException {
     if (Dir.equals(anywheresoftware.b4a.objects.streams.File.getDirAssets())) {
       if (anywheresoftware.b4a.objects.streams.File.virtualAssetsFolder != null) {
         return anywheresoftware.b4a.objects.streams.File.OpenInput(anywheresoftware.b4a.objects.streams.File.virtualAssetsFolder,
             anywheresoftware.b4a.objects.streams.File.getUnpackedVirtualAssetFile(File));
       }
       return anywheresoftware.b4a.objects.streams.File.OpenInput(BA.applicationContext.getAssets().openFd(File.toLowerCase(BA.cul)), 1);
     }
     else {
       return anywheresoftware.b4a.objects.streams.File.OpenInput(anywheresoftware.b4a.objects.streams.File.Combine(Dir, File), 1);
     }
   }