Workaround to get passed the broken install flow

For fresh installs the PM does not set the app uid before invoking
dexopt; so we would always get a bogus GID.

This is a temporary workaround which fixes the GID of newly
installed apps to an arbitrary UNKNOWN gid.

Test: adb install
Bug: 64548938
Bug: 69331247

(cherry picked from commit a73e165c)

Change-Id: I6438ec8cfca88df813e166f9ef5821e62faf524a