Fix AutoRevokeTest flakiness

There were some flaky failures caused by dummy package not being
visible to auto revoke at the time of running.
Only reproducible on acloud.
This adds a delay after install to (hopefully) address that

Fixes: 159948496
Fixes: 160016759
Test: Test passes 4/5 before fix, 5/5 after
Change-Id: I903f41320b8440aeadad63f55643630ddd6e289b
1 file changed