Perform MOBIKE when data stall is suspected on VCN network

This commit updates VCN  to listen to the connectivity
diagnostics callback so that when there is a suspected data stall
VCN will call into IKE to perform MOBIKE to recover.

Bug: 261499808
Test: atest FrameworksVcnTests (new tests), CtsVcnTestCases
Change-Id: Ic8ec45870b7e5190db4fe6b8b7710f54e7fb61f4