Cleanup background activity starts for release.

This removes the parts of the feature that were only needed in beta
releases:
- Develper setting to force feature on or off.

Not to be submitted until after beta 5 is cut.

Bug: 131747138
Test: Still builds, developer settings still works.

Change-Id: I573761174317797aeb4df97cf1a2b1ce005c0715

src/com/android/settings/development/DevelopmentSettingsDashboardFragment.java

@@ -472,7 +472,6 @@ public class DevelopmentSettingsDashboardFragment extends RestrictedDashboardFra
         controllers.add(new ProfileGpuRenderingPreferenceController(context));
         controllers.add(new KeepActivitiesPreferenceController(context));
         controllers.add(new BackgroundProcessLimitPreferenceController(context));
-        controllers.add(new AllowBackgroundActivityStartsPreferenceController(context));
         controllers.add(new ShowFirstCrashDialogPreferenceController(context));
         controllers.add(new AppsNotRespondingPreferenceController(context));
         controllers.add(new NotificationChannelWarningsPreferenceController(context));