Support to build with AAPT2

To build with AAPT2, set "USE_AAPT2=true".
TODO: Support split apks and generated resources from other than renderscript.

Bug: 25958912
Change-Id: I19b1a038824ce5b2a3d3ffadbce3173c845193fc
diff --git a/core/android_manifest.mk b/core/android_manifest.mk
index 582bad4..b945ea9 100644
--- a/core/android_manifest.mk
+++ b/core/android_manifest.mk
@@ -22,9 +22,12 @@
 my_full_libs_manifest_files += $(foreach lib, $(LOCAL_STATIC_JAVA_AAR_LIBRARIES),\
   $(call intermediates-dir-for,JAVA_LIBRARIES,$(lib),,COMMON)/aar/AndroidManifest.xml)
 
+# With USE_AAPT2, we'll link in the built resource from the AAR.
+ifndef USE_AAPT2
 LOCAL_RESOURCE_DIR += $(foreach lib, $(LOCAL_STATIC_JAVA_AAR_LIBRARIES),\
   $(call intermediates-dir-for,JAVA_LIBRARIES,$(lib),,COMMON)/aar/res)
-endif
+endif  # USE_AAPT2
+endif  # LOCAL_STATIC_JAVA_AAR_LIBRARIES
 
 # Set up rules to merge library manifest files
 ifdef my_full_libs_manifest_files