Fix the aprotoc target for Windows.

Allows aprotoc.exe to be cross-compiled when building the Windows SDK.

Change-Id: I7e1eec945b5578e1fe6c368b128fe1f9396f491c

Android.mk

@@ -347,10 +347,14 @@ LOCAL_SRC_FILES := $(COMPILER_SRC_FILES)
 
 LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/android \
+    external/zlib \
     $(LOCAL_PATH)/src
 
 LOCAL_STATIC_LIBRARIES += libz
+
+ifneq ($(HOST_OS),windows)
 LOCAL_LDLIBS := -lpthread
+endif
 
 LOCAL_CFLAGS := $(IGNORED_WARNINGS)