libhevcenc: Update 32 bit chroma neon modules to avoid reading an extra byte am: 42fb245a7b am: 2a3b4e76f9

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libhevc/+/15163641

Change-Id: Iefe1492cbd50eef4975bd0a7893776cd3223d595