hiddenapi: Enable assign-all CHECK

Master-art builds now pass --no-force-assign-all to `hiddenapi`. This
enables us to turn a warning that on non-master-art builds all methods
and fields have flags assigned to them. This also fixes logspam on
buildbots.

Test: art/tools/buildbot-build.sh
Bug: 123143676
Change-Id: Id0b57dbe9b0bb809bf22de1fd3b922a0886833ec
1 file changed