property_contexts: strip blank lines and comments

Strip whitespace and comments from property_context files
to reduce size. On an aosp_x86_64 build it saves 851 bytes.

However, on builds with more synclines and comments, further
space savings can be realized.

Change-Id: I43caf1deaab53d4753c835918898c8982f477ef0
Signed-off-by: William Roberts <william.c.roberts@intel.com>

Android.mk

@@ -358,10 +358,10 @@ $(property_contexts.tmp): $(all_pcfiles_with_nl)
 
 
 $(LOCAL_BUILT_MODULE): PRIVATE_SEPOLICY := $(built_sepolicy)
-$(LOCAL_BUILT_MODULE): $(property_contexts.tmp) $(built_sepolicy) $(HOST_OUT_EXECUTABLES)/checkfc $(ACP)
+$(LOCAL_BUILT_MODULE): $(property_contexts.tmp) $(built_sepolicy) $(HOST_OUT_EXECUTABLES)/checkfc
 	@mkdir -p $(dir $@)
-	$(hide) $(ACP) $< $@
-	$(hide) $(HOST_OUT_EXECUTABLES)/checkfc -p $(PRIVATE_SEPOLICY) $<
+	$(hide) sed -e 's/#.*$$//' -e '/^$$/d' $< > $@
+	$(hide) $(HOST_OUT_EXECUTABLES)/checkfc -p $(PRIVATE_SEPOLICY) $@
 
 built_pc := $(LOCAL_BUILT_MODULE)
 all_pc_files :=
@@ -385,8 +385,8 @@ $(general_property_contexts.tmp): $(addprefix $(LOCAL_PATH)/, property_contexts)
 $(LOCAL_BUILT_MODULE): PRIVATE_SEPOLICY := $(built_general_sepolicy)
 $(LOCAL_BUILT_MODULE): $(general_property_contexts.tmp) $(built_general_sepolicy) $(HOST_OUT_EXECUTABLES)/checkfc $(ACP)
 	@mkdir -p $(dir $@)
-	$(hide) $(ACP) $< $@
-	$(hide) $(HOST_OUT_EXECUTABLES)/checkfc -p $(PRIVATE_SEPOLICY) $<
+	$(hide) sed -e 's/#.*$$//' -e '/^$$/d' $< > $@
+	$(hide) $(HOST_OUT_EXECUTABLES)/checkfc -p $(PRIVATE_SEPOLICY) $@
 
 general_property_contexts.tmp :=