Add mapping files for 28.0.[ignore.]cil

Steps taken to produce the mapping files:

1. Add prebuilts/api/28.0/[plat_pub_versioned.cil|vendor_sepolicy.cil]
from the /vendor/etc/selinux/[plat_pub_versioned.cil|vendor_sepolicy.cil]
files built on pi-dev with lunch target aosp_arm64-eng

2. Add new file private/compat/28.0/28.0.cil by doing the following:
- copy /system/etc/selinux/mapping/28.0.cil from pi-dev aosp_arm64-eng
device to private/compat/28.0/28.0.cil
- remove all attribute declaration statement (typeattribute ...) and
sort lines alphabetically
- some selinux types were added/renamed/deleted w.r.t 28 sepolicy.
Find all such types using treble_sepolicy_tests_28.0 test.
- for all these types figure out where to map them by looking at
27.0.[ignore.]cil files and add approprite entries to 28.0.[ignore.]cil.

This change also enables treble_sepolicy_tests_28.0 and install 28.0.cil
mapping onto the device.

Bug: 72458734
Test: m selinux_policy
Change-Id: I90e17c0b43af436da4b62c16179c198b5c74002c