zenfone9: Unset BUILD_BROKEN_DUP_RULES

Overriden commands? Not anymore.

Change-Id: Id435e0fda13babadd5fbc2fe1c790e5a1fdba6df
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 6a5a38b..06a8b27 100755
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -85,7 +85,6 @@
 
 # Broken flags
 BUILD_BROKEN_CLANG_PROPERTY := true
-BUILD_BROKEN_DUP_RULES := true
 BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true
 
 # Camera