Assign the bit calculation as long to prevent overflow

The value should be assigned as a long to do the bit calculation
as the mNetworkCapabilities is intended to be a long. Otherwise,
the value will be temporary assigned into an integer then
assigned to the target long. When the bit shift calculation
is out of the integer scope, the calculation will overflow and
result in unexpected bebavior.

Without assigning to a long, ConnectivityServiceTest will get
Out-Of-Memory in StringBuilder while generating toString() in
NetworkCapabilities after updating tests to verify
NET_CAPABILITY_VSIM and NET_CAPABILITY_BIP.

Bug: 130869457
Test: atest FrameworksNetTests
Change-Id: I4d34c1215c7efb6dc352c314107792e3fa512ad7