Revert "Make OpenJDK 8 the default"

Temporary revert to help out Brillo folks.
It will be resubmitted tomorrow.

This reverts commit 4495f6afb8c23950c24dc9ee114050582da08f05.

Change-Id: Id378c7d3a6e72e9be50f9404b19d5763568987a5
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 1b65611..f791884 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -209,7 +209,7 @@
                 \@$(PRIVATE_SRC_LIST_FILE) \
                 -J-Xmx1024m \
                 -XDignore.symbol.file \
-                $(if $(LEGACY_USE_JAVA7),,-Xdoclint:none) \
+                $(if $(EXPERIMENTAL_USE_JAVA8),-Xdoclint:none) \
                 $(PRIVATE_PROFILING_OPTIONS) \
                 $(addprefix -classpath ,$(PRIVATE_CLASSPATH)) \
                 $(addprefix -bootclasspath ,$(PRIVATE_BOOTCLASSPATH)) \