fs_config: drop fs_config_files/dirs PRODUCT_PACKAGES requirement

When configuring fs_config_files or fs_config_dirs for file_system
capabilities, drop the requirement that OEMs must add the target
to PRODUCT_PACKAGES. This limits the configuration requirement
to only needing to set the new and preferred TARGET_FS_CONFIG_GEN
or the older TARGET_ANDROID_FILESYSTEM_CONFIG_H method.

Test: That only setting TARGET_FS_CONFIG_GEN results in passwd and
group in the build image.
Change-Id: I818854fa1b3e94edaff59a32bd7cf23cf9b504aa
Signed-off-by: William Roberts <william.c.roberts@intel.com>
diff --git a/tools/fs_config/Android.mk b/tools/fs_config/Android.mk
index 0734cf6..3d784a7 100644
--- a/tools/fs_config/Android.mk
+++ b/tools/fs_config/Android.mk
@@ -72,6 +72,19 @@
 my_fs_config_h := $(LOCAL_PATH)/default/$(ANDROID_FS_CONFIG_H)
 endif
 
+# We only include targets for:
+# fs_config_files
+# fs_config_dirs
+# If TARGET_FS_CONFIG_GEN or TARGET_ANDROID_FILESYSTEM_CONFIG_H
+# is set.
+#
+# We only include targets for:
+# passwd
+# group
+# If TARGET_FS_CONFIG_GEN is set.
+#
+ifneq ($(TARGET_FS_CONFIG_GEN)$(TARGET_ANDROID_FILESYSTEM_CONFIG_H),)
+
 ##################################
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := fs_config_generate.c
@@ -138,6 +151,10 @@
 	@mkdir -p $(dir $@)
 	$< -F -o $@
 
+endif # TARGET_FS_CONFIG_GEN or TARGET_ANDROID_FILESYSTEM_CONFIG_H
+
+# The newer passwd/group targets are only generated if you
+# use the new TARGET_FS_CONFIG_GEN method.
 ifneq ($(TARGET_FS_CONFIG_GEN),)
 
 ##################################