Updated git submodules

Project: odlparent master e7737d520df1561acb42ca0f255f6d2f3ec60b3d

Bump Checkstyle from 6.16 to 7.6.1

This (likely) requires some tweaks in projects enforcing CS;
needs testing using https://wiki.opendaylight.org/view/EvolvingCheckstyle

Motivated by having had to fix
https://git.opendaylight.org/gerrit/#/c/54978/

Change-Id: Ibef1cbb06e8e3d28a44b687562ebfc400d403b32
Signed-off-by: Michael Vorburger <vorburger@redhat.com>

diff --git a/docs/submodules/odlparent b/docs/submodules/odlparent
index 350202f3e12a11a903d84be457e487fe83ad81c2..e7737d520df1561acb42ca0f255f6d2f3ec60b3d 160000 (submodule)
--- a/docs/submodules/odlparent
+++ b/docs/submodules/odlparent
@@ -1 +1 @@
-Subproject commit 350202f3e12a11a903d84be457e487fe83ad81c2
+Subproject commit e7737d520df1561acb42ca0f255f6d2f3ec60b3d