Add 2 board configs for car emulators

Automotive emulator images have the same device name as the phone
emulators. Different device names help differentiating them in
the console.

1. add generic_car_x86_64 board as a wrapper of 64bit only board
2. add generic_car_x86 board as a wrapper of generic_86
3. change the PRODUCT_DEVICE accordingly.

Test: Manually launch the emualtor, check fingerprint
Bug: 170507246
Change-Id: Ibaac240b112bc93ed93549909799a1491e78c844
Merged-In: Ibaac240b112bc93ed93549909799a1491e78c844
6 files changed