Add a verbose option to RunCommand in build_image.py

Make the build log less verbose; also print the result for
AdjustPartitionSizeForVerity().

Bug: 65292710
Test: Run add_img_to_target_files with and without "-v" and check
the logs.

Change-Id: Icdc86197ce69db036658ea9e77cc4ebe1750463b
1 file changed