CTS test for VpnService.isAlwaysOn & .isLockdownEnabled.

Test cases that expect to get "true" returned are part of
devicepolicy tests since it is hard to set up always-on
configuration without device/profile owner.

Test: atest MixedDeviceOwnerTest#testAlwaysOnVpn
Test: atest HostsideVpnTests#testIsAlwaysOnIsLockdown
Bug: 72628179
Change-Id: I7fceab93a1d2d0255611f7a788391540e0dddccb
6 files changed