Let Zygote talk to init

Change-Id: I31ee0c105c11195873374146daf6c5647975b581
sepolicy: Fix a few denials

 * Zygote needs to set system properties

Change-Id: Ic570830cb4fcc3c0806ae775b9258350d2c90d24
sepolicy: Fix more denials

 * Zygote needs to fork certan things

Change-Id: I643eace5af71dbd45a3c55518c516ea45bdefe07

Conflicts:
	installd.te