Remove three board_avb_* args from META/misc_info.txt.

board_avb_algorithm and board_avb_key_path are overlapping with
avb_signing_args. In core/Makefile, only avb_signing_args (i.e.
INTERNAL_AVB_SIGNING_ARGS) will be used in the AVB-signing command. It
covers the contents in board_avb_{algorithm,key_path}. We should do the
same thing in tools/releasetools to avoid potential inconsistency.

This CL cleans up the logic in tools/releasetools, by always using
avb_signing_args. This also allows easier signing key replacement (so we
can replace the key/algorithm/signer in 'avb_signing_args').

board_avb_system_add_hashtree_footer_args is unused in releasetools
script, and the same information has been covered by
system_avb_add_hashtree_footer_args. This CL removes this arg as well.

Test: `m dist`. Then a) check the removed three args no longer exist in
      META/misc_info.txt; b) check that rebuilding images with
      add_img_to_target_files.py uses the same parameters.
Change-Id: I7db890b5c942de5b6868d8d1ebf937586d4729c0
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index c022d24..652fadf 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -345,16 +345,6 @@
     print("%-25s = (%s) %s" % (k, type(v).__name__, v))
 
 
-def AppendAVBSigningArgs(cmd):
-  """Append signing arguments for avbtool."""
-  keypath = OPTIONS.info_dict.get("board_avb_key_path", None)
-  algorithm = OPTIONS.info_dict.get("board_avb_algorithm", None)
-  if not keypath or not algorithm:
-    algorithm = "SHA256_RSA4096"
-    keypath = "external/avb/test/data/testkey_rsa4096.pem"
-  cmd.extend(["--key", keypath, "--algorithm", algorithm])
-
-
 def _BuildBootableImage(sourcedir, fs_config_file, info_dict=None,
                         has_ramdisk=False, two_step_image=False):
   """Build a bootable image from the specified sourcedir.
@@ -491,12 +481,12 @@
 
   # AVB: if enabled, calculate and add hash to boot.img.
   if info_dict.get("board_avb_enable", None) == "true":
-    avbtool = os.getenv('AVBTOOL') or OPTIONS.info_dict["avb_avbtool"]
-    part_size = info_dict.get("boot_size", None)
+    avbtool = os.getenv('AVBTOOL') or info_dict["avb_avbtool"]
+    part_size = info_dict["boot_size"]
     cmd = [avbtool, "add_hash_footer", "--image", img.name,
            "--partition_size", str(part_size), "--partition_name", "boot"]
-    AppendAVBSigningArgs(cmd)
-    args = info_dict.get("board_avb_boot_add_hash_footer_args", None)
+    cmd.extend(shlex.split(info_dict["avb_signing_args"]))
+    args = info_dict.get("board_avb_boot_add_hash_footer_args")
     if args and args.strip():
       cmd.extend(shlex.split(args))
     p = Run(cmd, stdout=subprocess.PIPE)