sparse_img.py --get_partition_size return size of partition

Also, move code from build_super_image.py to sparse_img.py.

Test: sparse_img.py on sparse and non-sparse images
Bug: 122377935
Change-Id: Ie91fdfdbb54298ea27eb20d1b5363aeb1470356e

tools/releasetools/build_super_image.py

@@ -58,16 +58,8 @@ logger = logging.getLogger(__name__)
 UNZIP_PATTERN = ["IMAGES/*", "META/*"]
 
 
-def GetPartitionSizeFromImage(img):
-  try:
-    simg = sparse_img.SparseImage(img)
-    return simg.blocksize * simg.total_blocks
-  except ValueError:
-    return os.path.getsize(img)
-
-
 def GetArgumentsForImage(partition, group, image=None):
-  image_size = GetPartitionSizeFromImage(image) if image else 0
+  image_size = sparse_img.GetImagePartitionSize(image) if image else 0
 
   cmd = ["--partition",
          "{}:readonly:{}:{}".format(partition, image_size, group)]