Update comments for kUnsupportedClassLoaderContextEncoding. am: 122ce6af4c

Original change: https://android-review.googlesource.com/c/platform/art/+/2375892

Change-Id: I073bfc5591749ca4be9ab64cae4abb19b42056fe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>