Add back download_app_package to lib.sh

Author: Serock3

test/scripts/utils/lib.sh

@@ -284,3 +284,31 @@ function build_current_version {
         echo "GUI e2e executable for current version already exists at $gui_test_bin, skipping build"
     fi
 }
+
+function download_app_package {
+    local version=$1
+    local os=$2
+    local package_repo=""
+
+    if is_dev_version "$version"; then
+        package_repo="${BUILD_DEV_REPOSITORY}"
+    else
+        package_repo="${BUILD_RELEASE_REPOSITORY}"
+    fi
+
+    local filename
+    filename=$(get_app_filename "$version" "$os")
+    local url="${package_repo}/$version/$filename"
+
+    local package_dir
+    package_dir=$(get_package_dir)
+    if [[ ! -f "$package_dir/$filename" ]]; then
+        echo "Downloading build for $version ($os) from $url"
+        if ! curl -sf -o "$package_dir/$filename" "$url"; then
+            echo "Failed to download package from $url (hint: build may not exist, check the url)" 1>&2
+            exit 1
+        fi
+    else
+        echo "App package for version $version ($os) already exists at $package_dir/$filename, skipping download"
+    fi
+}