MT#55283 [debian] fix links backports for buster and focal

since 7e140e8a31 buster and focal
are generating these links:

> 09:47:43 lrwxrwxrwx root/root         0 2024-07-24 07:39 ./${env:deb_systemdsystemunitdir}/rtpengine.service -> rtpengine-daemon.service
> 09:47:43 lrwxrwxrwx root/root         0 2024-07-24 07:39 ./${env:deb_systemdsystemunitdir}/rtpengine@.service -> rtpengine-daemon@.service

Change-Id: Ie0dbace10f78252c43c45d92d323a44218384348
(cherry picked from commit 38fe21427d)
(cherry picked from commit 56411f0c65)

pkg/deb/backports/buster

@@ -21,6 +21,13 @@ sed -i -e 's/^execute_before_dh_auto_configure:/override_dh_auto_configure:/' ${
 sed -i -e 's/^execute_after_dh_installsystemd:/override_dh_installsystemd:\n\tdh_installsystemd/' ${DIST}/rules
 sed -i -e 's/^execute_before_dh_auto_install-indep:/override_dh_auto_install-indep:/' ${DIST}/rules
 sed -i -e '/^\tgzip -9 < README.md/a\\n\tdh_auto_install' ${DIST}/rules
+
+# fix links
+sed -i -e 's#${env:deb_systemdsystemunitdir}#/lib/systemd/system/#g' \
+  ${DIST}/rtpengine-recording-daemon.links
+sed -i -e 's#${env:deb_systemdsystemunitdir}#/lib/systemd/system/#g' \
+  ${DIST}/rtpengine-daemon.links
+
 # Add dwz override
 cat >> ${DIST}/rules <<'EOF'
 

pkg/deb/backports/focal

@@ -20,6 +20,13 @@ sed -i -e 's/debhelper-compat.*/debhelper-compat (= 12),/' ${DIST}/control
 sed -i -e 's/^execute_after_dh_installsystemd:/override_dh_installsystemd:\n\tdh_installsystemd/' ${DIST}/rules
 sed -i -e 's/^execute_before_dh_auto_install-indep:/override_dh_auto_install-indep:/' ${DIST}/rules
 sed -i -e '/^\tgzip -9 < README.md/a\\n\tdh_auto_install' ${DIST}/rules
+
+# fix links
+sed -i -e 's#${env:deb_systemdsystemunitdir}#/lib/systemd/system/#g' \
+  ${DIST}/rtpengine-recording-daemon.links
+sed -i -e 's#${env:deb_systemdsystemunitdir}#/lib/systemd/system/#g' \
+  ${DIST}/rtpengine-daemon.links
+
 # Add dwz override
 cat >> ${DIST}/rules <<'EOF'