Add new screen lock complexity permission

This permission will be used to gate
- a new api to get the screen lock complexity level
- the intent to prompt users to update the screen lock to a certain
complexity level

Bug: 111173457
Test: "adb shell pm list permissions" shows the new permission
      atest android.permission2.cts.PermissionPolicyTest

Change-Id: Ibdc2bfedf6936a59c1f35a13179e10fd68d6ed35