Network Test Coverage

Many cmdlets in the Network module are missing tests or do not fully test the functionality of the cmdlet. This is blocking the addition of -AsJob for these cmdlets because we cannot add tests for this functionality of the -AsJob parameter. Once the tests are updated to fully cover these cmdlets, the -AsJob parameter can be added (details [here](https://github.com/Azure/azure-powershell/wiki/PowerShell-Cmdlet-Design-Guidelines#asjob-parameter)).

## Cmdlets that need improved test coverage:
- [ ] Get-AzureRmVpnClientPackage: Asserts commented out.
- [ ] Remove-AzureRmVirtualNetworkGatewayConnection: Not actually testing if connection is deleted.
- [ ] Get-AzureRmExpressRouteCircuitARPTable: No asserts for cmdlet.
- [ ] Get-AzureRmExpressRouteCircuitRouteTableSummary: No asserts for cmdlet.
- [ ] Get-AzureRmExpressRouteCircuitRouteTable: No asserts for cmdlet.

## Additional work related to this issue
- [ ] Add AsJob parameter to each cmdlet with improved testing.

---

## Cmdlets without coverage (by team, upd. 12/13/2018)

## pgtm
- [ ] Get-AzureRmExpressRouteCircuitConnectionConfig
- [ ] Get-AzureRmExpressRouteCrossConnection
- [ ] Set-AzureRMExpressRouteCrossConnection
- [ ] Get-AzureRMExpressRouteCrossConnectionArpTable
- [ ] Get-AzureRMExpressRouteCrossConnectionRouteTable
- [ ] Get-AzureRMExpressRouteCrossConnectionRouteTableSummary
- [ ] Add-AzureRmExpressRouteCrossConnectionPeering
- [ ] Get-AzureRmExpressRouteCrossConnectionPeering
- [ ] Remove-AzureRmExpressRouteCrossConnectionPeering

## sdnnrp
- [ ] Get-AzureRmInterfaceEndpoint - can't tests without `New` cmdlet, ETA for fixes from owning team - February 2019

### Peering tests (skipped due to test framework constraints)
- [ ] Add-AzureVirtualNetworkPeering
- [ ] Get-AzureVirtualNetworkPeering
- [ ] Set-AzureVirtualNetworkPeering
- [ ] Remove-AzureVirtualNetworkPeering

## firewall
- [ ] AzureFirewallNetworkRuleProtocolHelper - need tests for cases such as `$rule.AddProtocol(“http”)`