store filesystem config info in target files at build time

Store a dump of the desired uid/gid/mode for every system file in the
target_files zip.  Modify ota_from_target_files to use this stored
information when it is available, instead of running fs_config from
the current client (which might be out of sync from the one where the
target_files zip was built).

b/2516887 - New android_filesystem_config.h needed

Change-Id: I8409a0265d1d50daad9c2bc033c99b74b8931b20

core/Makefile

@@ -869,6 +869,7 @@ $(BUILT_TARGET_FILES_PACKAGE): \
 		$(INSTALLED_ANDROID_INFO_TXT_TARGET) \
 		$(built_ota_tools) \
 		$(APKCERTS_FILE) \
+		$(HOST_OUT_EXECUTABLES)/fs_config \
 		| $(ACP)
 	@echo "Package target files: $@"
 	$(hide) rm -rf $@ $(zip_root)
@@ -934,6 +935,10 @@ endif
 	$(hide) echo "$(tool_extensions)" > $(zip_root)/META/tool-extensions.txt
 	@# Zip everything up, preserving symlinks
 	$(hide) (cd $(zip_root) && zip -qry ../$(notdir $@) .)
+	@# Run fs_config on all the system files in the zip, and save the output
+	$(hide) zipinfo -1 $@ | awk -F/ 'BEGIN { OFS="/" } /^SYSTEM\// {$$1 = "system"; print}' | $(HOST_OUT_EXECUTABLES)/fs_config > $(zip_root)/META/filesystem_config.txt
+	$(hide) (cd $(zip_root) && zip -q ../$(notdir $@) META/filesystem_config.txt)
+
 
 target-files-package: $(BUILT_TARGET_FILES_PACKAGE)