add symbol files to PDK release for debugging

- app_process is not in PDK, and this makes native debugging difficult
  So provide symbol file instead of source

Bug: 6774048

Change-Id: I1a3a86cf64d8f1d22cdb3a22714f508de963099b
diff --git a/core/Makefile b/core/Makefile
index a6974a3..1a36277 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -829,7 +829,8 @@
 	$(hide) rm -f $@
 	$(hide) cd $(dir $@) && zip -qry $(notdir $@) \
 		$(TARGET_COPY_OUT_SYSTEM) \
-		$(patsubst $(PRODUCT_OUT)/%, %, $(TARGET_OUT_NOTICE_FILES))
+		$(patsubst $(PRODUCT_OUT)/%, %, $(TARGET_OUT_NOTICE_FILES)) \
+		$(addprefix symbols/,$(PDK_SYMBOL_FILES_LIST))
 ifeq (true,$(PLATFORM_ZIP_ADD_JAVA))
 	$(hide) cd $(OUT_DIR) && zip -qry $(patsubst $(OUT_DIR)/%,%,$@) $(PDK_PLATFORM_JAVA_ZIP_CONTENTS)
 endif
diff --git a/core/pdk_config.mk b/core/pdk_config.mk
index ddf240c..77e9133 100644
--- a/core/pdk_config.mk
+++ b/core/pdk_config.mk
@@ -153,3 +153,16 @@
 endif # PDK_JAVA
 
 endif # BUILD_PDK
+
+ifneq (,$(filter platform platform-java, $(MAKECMDGOALS))$(filter true,$(TARGET_BUILD_PDK)))
+# files under $(PRODUCT_OUT)/symbols to help debugging.
+# Source not included to PDK due to dependency issue, so provide symbols instead.
+PDK_SYMBOL_FILES_LIST := \
+	system/bin/app_process
+
+ifdef PDK_FUSION_PLATFORM_ZIP
+# symbols should be explicitly pulled for fusion build
+$(foreach f,$(PDK_SYMBOL_FILES_LIST),\
+  $(eval $(call add-dependency,$(PRODUCT_OUT)/$(f),$(PRODUCT_OUT)/symbols/$(f))))
+endif # PLATFORM_ZIP
+endif # platform.zip build or PDK