Upgrade common-packer to v0.5.2

This patch pulls in the Git fix to install a more recent version
of Git instead of the severely out of date one provided by CentOS 7.

Change-Id: Ia7805e9236b094194bd711fa1dfb610ec0575642
Signed-off-by: Thanh Ha <zxiiro@gmail.com>

diff --git a/packer/common-packer b/packer/common-packer
index dbd3a53616793745f078c16eb62405ef6919907c..3cecc412b0339d8dca5121650fbb930c00fac20c 160000 (submodule)
--- a/packer/common-packer
+++ b/packer/common-packer
@@ -1 +1 @@
-Subproject commit dbd3a53616793745f078c16eb62405ef6919907c
+Subproject commit 3cecc412b0339d8dca5121650fbb930c00fac20c