Add BOARD_MOVE_RECOVERY_RESOURCES_TO_VENDOR_BOOT.

This variable indicates whether recovery resources are moved to
vendor_boot. If true:

- $OUT/recovery.img will not be built
- $OUT/recovery/root will be included in vendor_boot ramdisk

Bug: 156098440
Test: set to true and check output
Test: `m target-files-package` and manually inspect output
Change-Id: I56dda56bab7def1540f4fb506323e3e605620cd4