Fix typo of BOARD_PLAT_PUBLIC_SEPOLICY_DIR

Bug: 141880898
Test: mmma system/sepolicy
Change-Id: I001a584224876de966a55a51bee2dd698cb59e41
diff --git a/sunfish-sepolicy.mk b/sunfish-sepolicy.mk
index 93d0eea..0924c32 100644
--- a/sunfish-sepolicy.mk
+++ b/sunfish-sepolicy.mk
@@ -1,4 +1,4 @@
-ARD_PLAT_PUBLIC_SEPOLICY_DIR := device/google/sunfish-sepolicy/public
+BOARD_PLAT_PUBLIC_SEPOLICY_DIR := device/google/sunfish-sepolicy/public
 BOARD_PLAT_PRIVATE_SEPOLICY_DIR := device/google/sunfish-sepolicy/private
 
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