Support repacking super image with virtual AB

Bug: 155702857
Test: repack_super_image --ota-tools ./otatools.zip \
      --misc-info ./misc_info.txt ./super.img product= \
      system=system.img
Change-Id: I03f33969d3c033a47cf123f94d875a4b56d2d343
Merged-In: I03f33969d3c033a47cf123f94d875a4b56d2d343
(cherry picked from commit 3e8b7f96d83afd54f54133b86b6047da53991c80)
1 file changed