Add an additional layer of inheritance for `factory_tokay`,
`aosp_tokay`, and `aosp_tokay_fullmte`.
This change adds a common layer of inheritance for non-factory
products (tokay_generic.mk). This makes it easier to configure
factory and non-factory products differently.
Non-factory `tokay` products now inherits from
`device/google/caimito/tokay_generic.mk` which inherit from
`device/google/caimito/device-tokay.mk`.
aconfig flags: Flag: EXEMPT mechanical refactoring
build flags: Flag: EXEMPT mechanical refactoring
Bug: 336452008
Bug: 336706866
Test: lunch aosp_tokay-trunk_staging-userdebug && m
lunch aosp_tokay_fullmte-trunk_staging-userdebug && m
Change-Id: Ided24b5d180bcfdf8ff2b1f9964fa42c0c53ef99