Use libcore/known_oj_tags for the javadoc stage.

Helps us process (and discard) OpenJdk specific javadoc tags.

(cherry picked from commit 2c4f2843f4aa904c27dc78086bff039dbd295959)

Change-Id: Ib90ce70509fefa24608067db18cfc21c6c5d0590
1 file changed