Decouple security exception check test from ConnectivityServiceTest

Decouple security exception check test from ConnectivityServiceTest
to VpnManagerServiceTest.

These security exception tests landed in ConnectivityServiceTest
because of no VpnManagerServiceTest. Move the tests to the
VpnManagerServiceTest where is better place to put the VPN related
tests to reduce the size of ConnectivityServiceTest.

Bug: 230548427
Test: atest FrameworksNetTests
Change-Id: I94b691c4d1f63bd5226e3296e6d0160dcb03107c
2 files changed