Add an exemption to neverallow rule to use sockets from HAL servers only
for automotive build

Bug: 78901167
Test: assign this attribute to hal_vehicle_default and try to open
socket from HAL implementation
Test: verify that new CTS test will fail for non-automotive build with
this attribute buing used
Test: make cts && cts-tradefed run singleCommand cts --skip-device-info
 --skip-preconditions --abi arm64-v8a --module CtsSecurityHostTestCases
 -t android.security.cts.SELinuxHostTest

Change-Id: I27976443dad4fc5b7425c089512cac65bb54d6d9