Enable a prop to determine the new figerprint is enabled

VTS and some other tests would replace the system images with GSI. To
put the correct fingerprint in the test report, we need to know if the
new fingerprint format is in use. So, add a vendor build prop.

OEMs are reponsible for setting this build prop, or using other ways
to put the correct fingerprint in the test report.

Bug: 188824341
Test: boot the device, check build prop
Change-Id: I6bc7f01903865fc2c256d209debdab68cd9d1bb3
diff --git a/core/main.mk b/core/main.mk
index c45c1f2..e8c1ef9 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -311,6 +311,13 @@
 endif
 endif
 
+# Set the flag in vendor. So VTS would know if the new fingerprint format is in use when
+# the system images are replaced by GSI.
+ifeq ($(BOARD_USE_VBMETA_DIGTEST_IN_FINGERPRINT),true)
+ADDITIONAL_VENDOR_PROPERTIES += \
+    ro.vendor.build.fingerprint_has_digest=1
+endif
+
 ADDITIONAL_VENDOR_PROPERTIES += \
     ro.vendor.build.security_patch=$(VENDOR_SECURITY_PATCH) \
     ro.product.board=$(TARGET_BOOTLOADER_BOARD_NAME) \