Fix zygote handling of when secondary image is out of date.

Simple fix for case when primary image is current, but a secondary image
is out of date. Will want to do a cleaner fix in the future.

Bug: 27340451

(cherry-picked from commit b8510d2311964489342d8875ef7f5b681ba874b4)

Change-Id: I034f001834d84b2a4aa367da722543091a2a7b3a
1 file changed