Allow basic user data backup on Android

platform/android/export/export.cpp

@@ -857,6 +857,8 @@ class EditorExportPlatformAndroid : public EditorExportPlatform {
 
 		int xr_mode_index = p_preset->get("xr_features/xr_mode");
 
+		bool backup_allowed = p_preset->get("user_data_backup/allow");
+
 		Vector<String> perms;
 		// Write permissions into the perms variable.
 		_get_permissions(p_preset, p_give_internet, perms);
@@ -949,6 +951,10 @@ class EditorExportPlatformAndroid : public EditorExportPlatform {
 							}
 						}
 
+						if (tname == "application" && attrname == "allowBackup") {
+							encode_uint32(backup_allowed, &p_manifest.write[iofs + 16]);
+						}
+
 						if (tname == "instrumentation" && attrname == "targetPackage") {
 							string_table.write[attr_value] = get_package_name(package_name);
 						}
@@ -1684,6 +1690,8 @@ public:
 		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "screen/support_large"), true));
 		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "screen/support_xlarge"), true));
 
+		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "user_data_backup/allow"), false));
+
 		r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "command_line/extra_args"), ""));
 
 		r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "apk_expansion/enable"), false));

platform/android/export/gradle_export_util.h

@@ -258,10 +258,11 @@ String _get_activity_tag(const Ref<EditorExportPreset> &p_preset) {
 }
 
 String _get_application_tag(const Ref<EditorExportPreset> &p_preset) {
-	String manifest_application_text =
+	String manifest_application_text = vformat(
 			"    <application android:label=\"@string/godot_project_name_string\"\n"
-			"        android:allowBackup=\"false\" tools:ignore=\"GoogleAppIndexingWarning\"\n"
-			"        android:icon=\"@mipmap/icon\">\n\n";
+			"        android:allowBackup=\"%s\" tools:ignore=\"GoogleAppIndexingWarning\"\n"
+			"        android:icon=\"@mipmap/icon\">\n\n",
+			bool_to_string(p_preset->get("user_data_backup/allow")));
 
 	manifest_application_text += _get_activity_tag(p_preset);
 	manifest_application_text += "    </application>\n";