Use boot header version 4 for Cuttlefish

Test: Boot cuttlefish with bootloader changes for header v4
Bug: 173815685
Change-Id: I618b474295d35b11a03937d3dc9a4be42d7619f4
diff --git a/shared/BoardConfig.mk b/shared/BoardConfig.mk
index f5d421a..e9bccf0 100644
--- a/shared/BoardConfig.mk
+++ b/shared/BoardConfig.mk
@@ -221,7 +221,7 @@
 endif
 
 BOARD_INCLUDE_DTB_IN_BOOTIMG := true
-BOARD_BOOT_HEADER_VERSION := 3
+BOARD_BOOT_HEADER_VERSION := 4
 BOARD_MKBOOTIMG_ARGS += --header_version $(BOARD_BOOT_HEADER_VERSION)
 PRODUCT_COPY_FILES += \
     device/google/cuttlefish/dtb.img:dtb.img \