riscv64: Disable Nterp so that zygote doesn't SIGILL at boot.

This started to happen after https://r.android.com/2537050, which
introduced initial support for Nterp in ART, but left all stubs
unimplemented (crashing with SIGILL on execution).

Bug: 271573990
Test: make sure zygote does not SIGILL at boot:
      $ lunch aosp_cf_riscv64_phone-userdebug && m
      $ launch_cvd --gpu_mode=drm_virgl
      # grep logcat for SIGILL (in zygote64 process), observe none
Change-Id: I1ac53b57d66414d56b10cd3abb5ae8c25b42c05d
1 file changed