Collect NOTICE files for apps_only build.

In apps_only build (after running tapas or exporting TARGET_BUILD_APPS),
run "make notice_files" to collect and combine the NOTICE files of
modules that are needed by the apps.

Bug: 10445634
Change-Id: I6555bba1104e43b48c723c82143c46d444a75e80
diff --git a/core/Makefile b/core/Makefile
index da2454a..d83578b 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -507,6 +507,7 @@
 tools_notice_file_txt := $(HOST_OUT_INTERMEDIATES)/NOTICE.txt
 tools_notice_file_html := $(HOST_OUT_INTERMEDIATES)/NOTICE.html
 
+ifndef TARGET_BUILD_APPS
 kernel_notice_file := $(TARGET_OUT_NOTICE_FILES)/src/kernel.txt
 pdk_fusion_notice_files := $(filter $(TARGET_OUT_NOTICE_FILES)/%, $(ALL_PDK_FUSION_FILES))
 
@@ -539,6 +540,7 @@
 ifeq ($(ONE_SHOT_MAKEFILE),)
 ALL_DEFAULT_INSTALLED_MODULES += $(installed_notice_html_gz)
 endif
+endif  # TARGET_BUILD_APPS
 
 # The kernel isn't really a module, so to get its module file in there, we
 # make the target NOTICE files depend on this particular file too, which will