[incfs] Add time measurement for native libs extraction

Use the "incremental.perflogging" boolean system property
to enable it

+ a bunch of code cleanups

Bug: 152913040
Test: manual

Change-Id: I1cd259ff5821a47ce055003049f77cbf43eba24a
diff --git a/services/incremental/IncrementalService.h b/services/incremental/IncrementalService.h
index ff69633..7ebc41d 100644
--- a/services/incremental/IncrementalService.h
+++ b/services/incremental/IncrementalService.h
@@ -158,6 +158,8 @@
     };
 
 private:
+    static const bool sEnablePerfLogging;
+
     struct IncFsMount {
         struct Bind {
             StorageId storage;
@@ -231,8 +233,10 @@
     void deleteStorage(IncFsMount& ifs);
     void deleteStorageLocked(IncFsMount& ifs, std::unique_lock<std::mutex>&& ifsLock);
     MountMap::iterator getStorageSlotLocked();
-    std::string normalizePathToStorage(const IfsMountPtr incfs, StorageId storage,
+    std::string normalizePathToStorage(const IfsMountPtr& incfs, StorageId storage,
                                        std::string_view path);
+    std::string normalizePathToStorageLocked(IncFsMount::StorageMap::iterator storageIt,
+                                             std::string_view path);
 
     int applyStorageParams(IncFsMount& ifs);