Data-binding integration.

- Set up LOCAL_JAVACFLAGS to run annotation processing.
- Set up a new intermediate directory $(data_binding_intermediates) to
  contain data-binding intermediate files.
- The annotation generated code is generated to
  $(data_binding_intermediates)/anno-src. The code will be automatically
  included by javac, so no need to store it in
  $(LOCAL_INTERMEDIATE_SOURCE_DIR).
- Set up rules to run DATA_BINDING_COMPILER. The generated code will be
  put in $(LOCAL_INTERMEDIATE_SOURCE_DIR)/data-binding, so that it can
  be automatically included by $(compile-java); Other generated files
  are put in in subdirs of $(data_binding_intermediates). The generated
  resource dir replaces the app's original LOCAL_RESOURCE_DIR.

Also fixed transform-jar-to-jack on prebuilt aar.

Bug: 19945740
Change-Id: I42d9b0e5cd48cf2dce4488298a960b3c95602beb
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index e605dcc..4b0884d 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -182,6 +182,7 @@
 LOCAL_DPI_FILE_STEM:=
 LOCAL_SANITIZE:=
 LOCAL_SANITIZE_RECOVER:=
+LOCAL_DATA_BINDING:=
 
 # arch specific variables
 LOCAL_SRC_FILES_$(TARGET_ARCH):=