Deduce the NET_CAPABILITY_NOT_VCN_MANAGED capability from other
capabilities and user intention, which includes:
1. For the requests that don't have anything besides
VCN_SUPPORTED_CAPABILITIES, add the NOT_VCN_MANAGED to
allow the callers automatically utilize VCN networks
if available.
2. For the requests that explicitly add or remove
NOT_VCN_MANAGED, do not alter them to allow user fire
request that suits their need.
Test: atest NetworkRequestTest#testBypassingVcnForNonInternetRequest
Bug: 175662146
Change-Id: I9936894b9530a22fb186cfd25cbee0fced65b72b
2fc40da076