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/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index ac970d1..1d8090a 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -194,11 +194,11 @@
   # AVB-sign the image as needed.
   if OPTIONS.info_dict.get("board_avb_enable") == "true":
     avbtool = os.getenv('AVBTOOL') or OPTIONS.info_dict["avb_avbtool"]
-    part_size = OPTIONS.info_dict.get("dtbo_size")
+    part_size = OPTIONS.info_dict["dtbo_size"]
     # The AVB hash footer will be replaced if already present.
     cmd = [avbtool, "add_hash_footer", "--image", img.name,
            "--partition_size", str(part_size), "--partition_name", "dtbo"]
-    common.AppendAVBSigningArgs(cmd)
+    cmd.extend(shlex.split(OPTIONS.info_dict["avb_signing_args"]))
     args = OPTIONS.info_dict.get("board_avb_dtbo_add_hash_footer_args")
     if args and args.strip():
       cmd.extend(shlex.split(args))
@@ -349,7 +349,7 @@
     cmd.extend(["--include_descriptors_from_image", dtbo_img_path])
   if OPTIONS.info_dict.get("system_root_image") == "true":
     cmd.extend(["--setup_rootfs_from_kernel", system_img_path])
-  common.AppendAVBSigningArgs(cmd)
+  cmd.extend(shlex.split(OPTIONS.info_dict["avb_signing_args"]))
   args = OPTIONS.info_dict.get("board_avb_make_vbmeta_image_args")
   if args and args.strip():
     cmd.extend(shlex.split(args))