Fix to check image_strong_intern table when inserting weaks.
Fix to check image_strong_intern table when inserting weaks.

The ExpatSaxParserTest.testNameSpaces test found that the empty string
"" would be .equals() another instance of the empty string, but they
weren't ==. The bug was that weak references were not checking the
image_strong_interns_ table before creating a weak reference.

Change-Id: I096eaee09973ccd19ca180ca07ac9438c2549296

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst