Merge "Document newly updated NDK/Media constants" into udc-dev am: 2bdb535e am: 06e4b174

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/22080102



Change-Id: Ia1de3165ce94d4bfaf89a0a879a6c98aec4ee242
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>