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

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

Change-Id: I9fa93b1d6baed016244b2f33d8cc3b1fdde78bf4
Signed-off-by: Automerger Merge Worker <[email protected]>