Remove duplicate src:dest pairs in PRODUCT_COPY_FILES

Before setting up the rules.

Change-Id: Ifedbc0e988895a899cae315dc730a152bae91ae2

core/Makefile

@@ -35,8 +35,13 @@ define check-product-copy-files
 $(if $(filter %.apk, $(1)),$(error \
     Prebuilt apk found in PRODUCT_COPY_FILES: $(1), use BUILD_PREBUILT instead!))
 endef
-unique_product_copy_files_destinations :=
+# filter out the duplicate <source file>:<dest file> pairs.
+unique_product_copy_files_pairs :=
 $(foreach cf,$(PRODUCT_COPY_FILES), \
+    $(if $(filter $(unique_product_copy_files_pairs),$(cf)),,\
+        $(eval unique_product_copy_files_pairs += $(cf))))
+unique_product_copy_files_destinations :=
+$(foreach cf,$(unique_product_copy_files_pairs), \
     $(eval _src := $(call word-colon,1,$(cf))) \
     $(eval _dest := $(call word-colon,2,$(cf))) \
     $(if $(filter $(unique_product_copy_files_destinations),$(_dest)), \
@@ -47,6 +52,7 @@ $(foreach cf,$(PRODUCT_COPY_FILES), \
             $(eval $(call copy-one-file,$(_src),$(_fulldest)))) \
         $(eval ALL_DEFAULT_INSTALLED_MODULES += $(_fulldest)) \
         $(eval unique_product_copy_files_destinations += $(_dest))))
+unique_product_copy_files_pairs :=
 unique_product_copy_files_destinations :=
 
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