Move extra VNDKs to /system_ext

Extra VNDKs are now installed under /system_ext in APEX format with
a phony target "vndk_apex_snapshot_package".

There are still files remained in /system/etc(*.libraries.<VER>.txt)
which are installed with "vndk_snapshot_packages".

These files are already packaged into VNDK APEXes, but linkerconfig and
libnativeloader still use them from /system/etc.(b/145184886)

Bug: 137802149
Test: lunch aosp_arm64
  && flash system.img on Q device
  && boot

Change-Id: I94c340d6f1c1af6ab1ae93c22b0a98fd4c10262e

target/product/gsi/Android.mk

@@ -162,10 +162,14 @@ endif
 # TODO(b/141450808): remove following VNDK phony targets when **.libraries.txt files are provided by apexes.
 LOCAL_REQUIRED_MODULES := \
     $(foreach vndk_ver,$(PRODUCT_EXTRA_VNDK_VERSIONS),vndk_v$(vndk_ver)_$(TARGET_ARCH)$(_binder32))
-LOCAL_REQUIRED_MODULES += $(foreach vndk_ver,$(PRODUCT_EXTRA_VNDK_VERSIONS),com.android.vndk.v$(vndk_ver))
 _binder32 :=
 include $(BUILD_PHONY_PACKAGE)
 
+include $(CLEAR_VARS)
+LOCAL_MODULE := vndk_apex_snapshot_package
+LOCAL_REQUIRED_MODULES := $(foreach vndk_ver,$(PRODUCT_EXTRA_VNDK_VERSIONS),com.android.vndk.v$(vndk_ver))
+include $(BUILD_PHONY_PACKAGE)
+
 endif # BOARD_VNDK_VERSION is set
 
 #####################################################################

target/product/media_system_ext.mk

@@ -22,3 +22,4 @@ $(call inherit-product, $(SRC_TARGET_DIR)/product/base_system_ext.mk)
 
 # /system_ext packages
 PRODUCT_PACKAGES += \
+    vndk_apex_snapshot_package \