Fix build issue for apparmor when systemd is used

When systemd is used as system init manager, there is a build issue complains
"can't found apparmor.service". This patch fix it.

Signed-off-by: Jinliang Li <jinliang.li@linux.alibaba.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

recipes-security/AppArmor/apparmor_2.11.0.bb

@@ -104,6 +104,11 @@ do_install () {
 
 	install ${WORKDIR}/apparmor ${D}/${INIT_D_DIR}/apparmor
 	install ${WORKDIR}/functions ${D}/lib/apparmor
+	if [ "${VIRTUAL-RUNTIME_init_manager}" = "systemd" ]; then
+		install -d ${D}${systemd_system_unitdir}
+		install ${WORKDIR}/apparmor.service \
+			${D}${systemd_system_unitdir}
+	fi
 }
 
 do_compile_ptest () {