Fix string deduplication for multi-image extensions.

Test: WITH_TIDY=1 m
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boots.
Bug: 153104371
Bug: 152037801
Change-Id: Ib91e7a13047d7da78deb855a6713a1a5d9044463
1 file changed