Revert "Squashed commit of all the sepolicy changes from SEAndroid"

This reverts commit 1c48643a481339e46378a100c2ebc484462cbc59.
Revert "Move init_shell domain definition and common rules to core sepolicy."

This reverts commit c8a0a76aff43cce552f1c7370fdf858f15fa959a.
Revert "Initial SELinux policy."

This reverts commit 50da8630f219f074b1a04c8c0d8105a2e12fd5c0.