init: log services requested restart

We have a case where a service is requested to be started and does
not appear to be running, but we see no indication that it is
actually starting. This log should be enough information to see
if init is in a bad state.

Bug: 232297944
Test: doesn't add too much spam
    ~/android/aosp/system/core/init :) adb logcat -d | grep "requested start" | wc -l
    42
Change-Id: Ic07f250c98b200b9e5b4432200c3668c6ca0ff35
Merged-In: Ic07f250c98b200b9e5b4432200c3668c6ca0ff35

init/service.cpp

@@ -547,6 +547,10 @@ Result<void> Service::Start() {
         if ((flags_ & SVC_ONESHOT) && disabled) {
             flags_ |= SVC_RESTART;
         }
+
+        LOG(INFO) << "service '" << name_
+                  << "' requested start, but it is already running (flags: " << flags_ << ")";
+
         // It is not an error to try to start a service that is already running.
         reboot_on_failure.Disable();
         return {};