Use LOCAL_ADDITIONAL_M4DEFS for file_contexts

Pass LOCAL_ADDITIONAL_M4DEFS to m4 when building vendor_file_contexts
and odm_file_contexts. The build command attempts to use
PRIVATE_ADDITIONAL_M4DEFS - but this is not set in the target-specific
variables.

This allows using custom M4 macros when building non-platform
file_contexts.

Change-Id: I5fa8d9ec91f1a97bee1dd735ba85af93eef91252

Android.mk

@@ -961,6 +961,7 @@ vendor_fcfiles_with_nl := $(call add_nl, $(vendor_fc_files), $(built_nl))
 
 $(LOCAL_BUILT_MODULE): PRIVATE_FC_FILES := $(vendor_fcfiles_with_nl)
 $(LOCAL_BUILT_MODULE): PRIVATE_SEPOLICY := $(built_sepolicy)
+$(LOCAL_BUILT_MODULE): PRIVATE_ADDITIONAL_M4DEFS := $(LOCAL_ADDITIONAL_M4DEFS)
 $(LOCAL_BUILT_MODULE): PRIVATE_FC_SORT := $(HOST_OUT_EXECUTABLES)/fc_sort
 $(LOCAL_BUILT_MODULE): $(HOST_OUT_EXECUTABLES)/checkfc $(HOST_OUT_EXECUTABLES)/fc_sort \
 $(vendor_fcfiles_with_nl) $(built_sepolicy)
@@ -988,6 +989,7 @@ odm_fcfiles_with_nl := $(call add_nl, $(odm_fc_files), $(built_nl))
 
 $(LOCAL_BUILT_MODULE): PRIVATE_FC_FILES := $(odm_fcfiles_with_nl)
 $(LOCAL_BUILT_MODULE): PRIVATE_SEPOLICY := $(built_sepolicy)
+$(LOCAL_BUILT_MODULE): PRIVATE_ADDITIONAL_M4DEFS := $(LOCAL_ADDITIONAL_M4DEFS)
 $(LOCAL_BUILT_MODULE): PRIVATE_FC_SORT := $(HOST_OUT_EXECUTABLES)/fc_sort
 $(LOCAL_BUILT_MODULE): $(HOST_OUT_EXECUTABLES)/checkfc $(HOST_OUT_EXECUTABLES)/fc_sort \
 $(odm_fcfiles_with_nl) $(built_sepolicy)