releasetools: Remove the parsing of META/imagesizes.txt.

The file has been removed from target-files.zip since commit
c19a8d5590a4ffd42b37ceaca2d779b48e481f99 (Gingerbread), whose info has
been consolidated into META/misc_info.txt.

Test: `m dist`
Change-Id: Ic144457954f5742ea082dcd9ffbea71df4afe46e
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 0c87857..c4fb29b 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -221,21 +221,6 @@
             vendor_base_fs_file,))
         del d["vendor_base_fs_file"]
 
-  try:
-    data = read_helper("META/imagesizes.txt")
-    for line in data.split("\n"):
-      if not line:
-        continue
-      name, value = line.split(" ", 1)
-      if not value:
-        continue
-      if name == "blocksize":
-        d[name] = value
-      else:
-        d[name + "_size"] = value
-  except KeyError:
-    pass
-
   def makeint(key):
     if key in d:
       d[key] = int(d[key], 0)