reland: untrusted_app_29: add new targetSdk domain

Enforce new requirements on app with targetSdkVersion=30 including:
- No RTM_GETLINK on netlink route sockets.

Remove some of the repetitive descriptions in each untrusted_app_N.te
file, and instead refer to the description in
public/untrusted_app.te.

Bug: 141455849
Test: CtsSelinuxTargetSdkCurrentTestCases
Test: libcore.java.net.NetworkInterfaceTest#testGetNetworkInterfaces
Change-Id: I89553e48db3bc71f229c71fafeee9005703e5c0b
9 files changed