Include NetworkCapabilities and LinkProperties in DataStallReport.

DataStallReport is updated to include the NetworkCapabilities and Link
Properties for the Network being reported on. This provides a more
complete picture of the Network conditions when the suspected data stall
was detected.

Bug: 148966398
Test: atest FrameworksNetTests
Change-Id: I913cf18c348b9f688f9d2a3d25a71bc94eb8f000