Disable code_coverage.other for riscv64

code_coverage.policy.other is supposed to install a policy for the
"other" architecture, e.g. arm for arm64.  riscv64 doesn't have an
"other" architecture, disable the module.

Test: builds
Change-Id: Ic42c706dd9c1efe4b0fe9fa7c9823a2a379ba56b