Add more logs into dumpsys of VPN

For improving debuggability of VPN, this commit adds below logs
into dump section.
- Logical bits in Ikev2VpnProfile
- Underlying network cap change and link properties change
- Historical calls to set always on and lockdown mode
- CarrierConfig change history
- IKE events

Test: atest FrameworksNetTests
Test: "adb shell dumpsys vpn_management" with VPN connected
Change-Id: I1a7aa81b207a0fa3cdec08e839fd8916fbff0f3c