Add --remote to git submodule_update

This simply adds --remote to the git submodule update command.
This means that if a branch is defined in .gitmodules then we should track said branch when updating.

library/source_control/git

@@ -376,8 +376,8 @@ def submodule_update(git_path, module, dest):
         return (0, '', '')
     cmd = [ git_path, 'submodule', 'sync' ]
     (rc, out, err) = module.run_command(cmd, check_rc=True, cwd=dest)
-    cmd = [ git_path, 'submodule', 'update', '--init', '--recursive' ]
-    (rc, out, err) = module.run_command(cmd, cwd=dest)
+    cmd = [ git_path, 'submodule', 'update', '--init', '--recursive' ,'--remote' ]
+    (rc, out, err) = module.run_command(cmd)
     if rc != 0:
         module.fail_json(msg="Failed to init/update submodules")
     return (rc, out, err)