Revert "resolve: enable DynamicUser= for systemd-resolved.service"

This reverts commit 0187368cad.
(systemd.conf.m4 part was already reverted in 5b5d82615011b9827466b7cd5756da35627a1608.)

src/resolve/resolved-bus.c

@@ -1920,7 +1920,7 @@ int manager_connect_bus(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Failed to register dnssd enumerator: %m");
 
-        r = bus_request_name_async_may_reload_dbus(m->bus, NULL, "org.freedesktop.resolve1", 0, NULL);
+        r = sd_bus_request_name_async(m->bus, NULL, "org.freedesktop.resolve1", 0, NULL, NULL);
         if (r < 0)
                 return log_error_errno(r, "Failed to request name: %m");
 

test/networkd-test.py

@@ -67,6 +67,7 @@ def setUpModule():
             tmpmounts.append(d)
     if os.path.isdir('/run/systemd/resolve'):
         os.chmod('/run/systemd/resolve', 0o755)
+        shutil.chown('/run/systemd/resolve', 'systemd-resolve', 'systemd-resolve')
 
     # Avoid "Failed to open /dev/tty" errors in containers.
     os.environ['SYSTEMD_LOG_TARGET'] = 'journal'

units/systemd-resolved.service.in

@@ -14,7 +14,7 @@ Documentation=https://www.freedesktop.org/wiki/Software/systemd/resolved
 Documentation=https://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers
 Documentation=https://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients
 DefaultDependencies=no
-After=systemd-networkd.service
+After=systemd-sysusers.service systemd-networkd.service
 Before=network.target nss-lookup.target shutdown.target
 Conflicts=shutdown.target
 Wants=nss-lookup.target
@@ -26,10 +26,11 @@ RestartSec=0
 ExecStart=!!@rootlibexecdir@/systemd-resolved
 WatchdogSec=3min
 User=systemd-resolve
-DynamicUser=yes
 CapabilityBoundingSet=CAP_SETPCAP CAP_NET_RAW CAP_NET_BIND_SERVICE
 AmbientCapabilities=CAP_SETPCAP CAP_NET_RAW CAP_NET_BIND_SERVICE
+PrivateTmp=yes
 PrivateDevices=yes
+ProtectSystem=strict
 ProtectHome=yes
 ProtectControlGroups=yes
 ProtectKernelTunables=yes