Support disabling IPsec packet loss detector

Allow disabling detector for better configurability

Bug: 336638836
Test: atest FrameworksVcnTests(new tests) && atest CtsVcnTestCases
Flag: android.net.vcn.allow_disable_ipsec_loss_detector
Change-Id: Icd7183d12fb287399a500ea9c0ee4125c749275c