Move common 32/64 bits product settings to another files

Move the common 32/64 bits product settings from aosp_xxx.mk to

    target/product/treble_common_(32|64).mk

The original core_64_bit.mk is not match the GSI requirement,
and will be revised soon. So, clone the content of
core_64_bit.mk into treble_common_64.mk.

Bug: 64653300
Test: Build pass
Change-Id: I6154a5c4927287c703a874b5cbf6a7f0c2c3594c