Add methods for IKEv2/IPsec test mode profiles

This change adds the ability for IKEv2/IPsec VPN profiles to run on Test
Networks. If enabled, the IKEv2/IPsec VPN profiles will request ONLY
test networks.

Bug: 148582947
Test: FrameworksNetTests passing
Test: Added for testing
Change-Id: I2511b39b27a1e29ae97907cdb12728d13fb1628f