Allow several syscalls to app process

Several privileged syscalls are still needed before a zygote-fork hangs
over the execution to the apps.

Test: system starts, different apps run
Bug: 63944145
Bug: 76461821
Change-Id: I78da54dac509eb073bc2aa7b820a1f6b0c39a775
Merged-In: I78da54dac509eb073bc2aa7b820a1f6b0c39a775