Enable CFI by default but restrict CFI_INCLUDE_PATHS

This CL enables CFI on security sensitive components for product
configs that inherit core_64_bit.mk (and core_64_bit_only.mk). Note
that this only requests the build system to do so. Internal build
logic will dictate if this is actually enabled on the build or
not (CFI is currently disabled for ARM32 and MIPS for example).

In addition, this also restricts CFI_INCLUDE_PATHS and
PRODUCT_CFI_INCLUDE_PATHS to Arm64 architectures only. This helps
narrow which targets enable CFI out of the box.

Bug: 66301104
Test: CFI is enabled on aosp_* targets
Change-Id: I52af499dc34cd4b42fbfb1175f6a37aaf17b65dd