Unavailable DataLoader status.

This is a temporary failure, does not fail the session, but requires
caller to re-commit. E.g. there are connectivity issues which can be
fixed later.

Bug: b/153874006
Test: atest PackageManagerShellCommandTest PackageManagerShellCommandIncrementalTest IncrementalServiceTest
Change-Id: I02791a2963130dbecb510c4a7cafcf04f6245761
diff --git a/services/incremental/IncrementalService.h b/services/incremental/IncrementalService.h
index 81fbe74..d5c612d 100644
--- a/services/incremental/IncrementalService.h
+++ b/services/incremental/IncrementalService.h
@@ -187,6 +187,7 @@
         bool destroy();
 
         bool setTargetStatus(int status);
+        void setTargetStatusLocked(int status);
         bool waitForStatus(int status, Clock::duration duration);
 
         bool fsmStep();