untrusted_app_29: add new targetSdk domain

Enforce new requirements on app with targetSdkVersion=30 including:
- No bind() on netlink route sockets.
- 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
Change-Id: Iad4d142c0c13615b4710d378bc1feca4d125b6cc
9 files changed