Merge "Use ro.build.version.known_codenames sysprop for KNOWN_CODENAMES." am: 19c5ee8bf1 am: 247988066c

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1978331

Change-Id: Ifb3aec2d1e7aeb5aa24b6d1bf70ba6cd4fa987ed