Set PACKAGE_ environment in release.sh

Change-Id: I77122d6c76cac35a760d52bd3cf544cc0f0b5fdf
diff --git a/kokoro/release.sh b/kokoro/release.sh
index 581ab66..d8f26b3 100644
--- a/kokoro/release.sh
+++ b/kokoro/release.sh
@@ -15,6 +15,8 @@
 export PREBUILT_MODULES_ROOT=${KOKORO_GFILE_DIR}
 export PREBUILT_DOCKER_ROOT=${KOKORO_GFILE_DIR}
 export FETCH_PBUILDER_DIRECTORY=${KOKORO_GFILE_DIR}
+export PACKAGES_FETCH_ROOT_DIRECTORY=${KOKORO_GFILE_DIR}
+export PACKAGES_REVISION=.
 export DEBOOTSTRAP_TARBALL_REVISION=.
 export ROOTFS_REVISION=.
 export FETCH_PACKAGES=false