libziparchive: Fix build flags for targets that build with GCC

GCC pre 5.1 incorrectly warns when a C++11 struct is empty brace initialized
Struct s = {}.

Change-Id: Id5696aae32cea2d45072176c1d9abe8a4bddad68
diff --git a/libziparchive/Android.mk b/libziparchive/Android.mk
index 53c1b3b..8ff94d4 100644
--- a/libziparchive/Android.mk
+++ b/libziparchive/Android.mk
@@ -18,6 +18,10 @@
 source_files := zip_archive.cc zip_writer.cc
 test_files := zip_archive_test.cc zip_writer_test.cc entry_name_utils_test.cc
 
+# Incorrectly warns when C++11 empty brace {} initializer is used.
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61489
+common_cpp_flags := -Wno-missing-field-initializers
+
 include $(CLEAR_VARS)
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_SRC_FILES := ${source_files}
@@ -25,7 +29,7 @@
 LOCAL_SHARED_LIBRARIES := libutils libbase
 LOCAL_MODULE:= libziparchive
 LOCAL_CFLAGS := -Werror -Wall
-LOCAL_CPPFLAGS := -Wold-style-cast
+LOCAL_CPPFLAGS := -Wold-style-cast $(common_cpp_flags)
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
@@ -35,10 +39,7 @@
 LOCAL_MODULE:= libziparchive-host
 LOCAL_CFLAGS := -Werror
 LOCAL_CFLAGS_windows := -mno-ms-bitfields
-
-# Incorrectly warns when C++11 empty brace {} initializer is used.
-# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61489
-LOCAL_CFLAGS_windows += -Wno-missing-field-initializers
+LOCAL_CPPFLAGS := $(common_cpp_flags)
 
 LOCAL_MULTILIB := both
 LOCAL_MODULE_HOST_OS := darwin linux windows
@@ -51,6 +52,7 @@
 LOCAL_SHARED_LIBRARIES := libz-host liblog libbase
 LOCAL_MODULE:= libziparchive-host
 LOCAL_CFLAGS := -Werror
+LOCAL_CPPFLAGS := $(common_cpp_flags)
 LOCAL_MULTILIB := both
 include $(BUILD_HOST_SHARED_LIBRARY)
 
@@ -59,6 +61,7 @@
 LOCAL_MODULE := ziparchive-tests
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_CFLAGS := -Werror
+LOCAL_CPPFLAGS := $(common_cpp_flags)
 LOCAL_SRC_FILES := $(test_files)
 LOCAL_SHARED_LIBRARIES := liblog libbase
 LOCAL_STATIC_LIBRARIES := libziparchive libz libutils
@@ -67,9 +70,8 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := ziparchive-tests-host
 LOCAL_CPP_EXTENSION := .cc
-LOCAL_CFLAGS += \
-    -Werror \
-    -Wno-unnamed-type-template-args
+LOCAL_CFLAGS := -Werror
+LOCAL_CPPFLAGS := -Wno-unnamed-type-template-args $(common_cpp_flags)
 LOCAL_SRC_FILES := $(test_files)
 LOCAL_SHARED_LIBRARIES := libziparchive-host liblog libbase
 LOCAL_STATIC_LIBRARIES := \