Add a logging statement after soong ZIP runs in the
merge_target_files.py step.

Bug: 134681035
Test: Built a merged build and ensured that the new timestamp was
visible in the log.

Change-Id: Ia6bbda48c7f57afdb6482253eaf0b3b0ea067468
diff --git a/tools/releasetools/merge_target_files.py b/tools/releasetools/merge_target_files.py
index bacbfd0..f37c0ee 100755
--- a/tools/releasetools/merge_target_files.py
+++ b/tools/releasetools/merge_target_files.py
@@ -931,6 +931,7 @@
   ]
   logger.info('creating %s', output_target_files)
   common.RunAndWait(command, verbose=True)
+  logger.info('finished creating %s', output_target_files)
 
   # Create the OTA package from the merged target files package.