Android: Add a GN target for android.car

Bug: None
Change-Id: Ic7560fcb8d37fc2206a0a0e1c75d0746394b152a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4809315
Commit-Queue: Sam Maier <smaier@chromium.org>
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1187885}
NOKEYCHECK=True
GitOrigin-RevId: 1a3240eee7e762c4c24aa838dd98b4dece850ae8