Revert part of previous change.

allowBgActivityStartsOnServiceStart() should be called after it is
certain that the service start is allowed.

Bug: 157473819
Test: atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java
Change-Id: Ifcde7f18ea07e9cece84134a48848f84aa6db4ca

services/core/java/com/android/server/am/ActiveServices.java

@@ -493,11 +493,6 @@ public final class ActiveServices {
         }
 
         ServiceRecord r = res.record;
-
-        if (allowBackgroundActivityStarts) {
-            r.allowBgActivityStartsOnServiceStart();
-        }
-
         setFgsRestrictionLocked(callingPackage, callingPid, callingUid, service, r,
                 allowBackgroundActivityStarts);
 
@@ -710,6 +705,9 @@ public final class ActiveServices {
                         "Not potential delay (user " + r.userId + " not started): " + r);
             }
         }
+        if (allowBackgroundActivityStarts) {
+            r.allowBgActivityStartsOnServiceStart();
+        }
         ComponentName cmp = startServiceInnerLocked(smap, service, r, callerFg, addToStarting);
         return cmp;
     }