generate_constants_json: Add riscv64 arch_nr am: 38c215613d am: e8f9812cc9 am: 633e73cc52 am: 6576586ae0

Original change: https://android-review.googlesource.com/c/platform/external/minijail/+/2537030

Change-Id: I55f856b436ef9464ab9fd57078949a36ea8dd5f4
Signed-off-by: Automerger Merge Worker <[email protected]>