Allow wrapped app to send pid back to zygote.

Bug: 63566721
Bug: 63635227
Test: lunch angler-userdebug && m
Test: lunch angler-user && m
Test: lunch angler-user && m && fastboot flashall && m cts && cts-tradefed run commandAndExit cts-dev -m CtsWrapWrapDebugTestCases
Change-Id: Ie1b41c3eb124aa5ee321c124d0121a0e965f0f0e