Use blocklist sub-property in sanitize am: 49f6f6562f am: bc9b8380cc am: 6d8d3f03a7 am: 6c95651473

Original change: https://android-review.googlesource.com/c/platform/external/libaom/+/1375460

Change-Id: Iae908491eb60d2e1dcec72a60bd25b96722692cd