DNS Proxy support for Azure Firewall

[isra-fel]

Description

(Creating PR on behalf of @tejasshah7 as the original PR #11807 contains to many conflicts.)

These changes are to add support for DNS Proxy options to Azure Firewall command. 3 new parameters are added.

• DNSServers: Array of strings
• DNSEnableProxy: This can betrue/false with default being false

Allowed:
New-AzFirewall -Name "azFw" -ResourceGroupName $rgName -Location centralus -VirtualNetwork $vnet -PublicIpAddress $pip -DNSEnableProxy true -DNSServers @("10.10.10.1", "20.20.20.2")

Allowed only if no Network Rules have FQDNs:
New-AzFirewall -Name "azFw" -ResourceGroupName $rgName -Location centralus -VirtualNetwork $vnet -PublicIpAddress $pip -DNSRequireProxyForNetworkRules false

Only validation required is

• If DNSRequireProxyForNetworkRules is explicitly set to False with DNSProxy disabled too, then no Network Rules can have FQDNs. Default value is true

Checklist

• [x ] I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
  • the markdown help files have been regenerated using the commands listed here

[adxsdkps]

Can one of the admins verify this patch?

[isra-fel]

Also please fix the test.
Besides, we prefer "Dns" to "DNS" in our cmdlet interfaces, for example, Set-AzNetworkInterface -DnsServer

[anton-evseev]

Please use Network SDK version 19.21.0-preview (see #11814)

[tejasshah7]

Also please fix the test.
Besides, we prefer "Dns" to "DNS" in our cmdlet interfaces, for example, Set-AzNetworkInterface -DnsServer

Changed as per recommendation

[tejasshah7]

Also please fix the test.
Besides, we prefer "Dns" to "DNS" in our cmdlet interfaces, for example, Set-AzNetworkInterface -DnsServer

Changed as per recommendation

[tejasshah7]

@isra-fel

The test recording is NOT updated because local build no longer works for network-april branch after the SDK update. So the test recording here needs to be updated. If the branch itself could be fixed, that would be great.

I found a way to fix the build and test. I will upload the new test recording soon. Thx.

@isra-fel updated test checked in.

[isra-fel]

@tejasshah7 there are still cases failing.
Besides, please resolve the conflict in ChangeLog.md, as another network PR was merged.

[anton-evseev]

network-april was merged into master, so retargetting this PR too

[anton-evseev]

@tejasshah7 there are still issues with Firewall tests, could you please pull this rebased branch and resolve them?

[tejasshah7]

@tejasshah7 there are still issues with Firewall tests, could you please pull this rebased branch and resolve them?

@number213 Rebased and fixed

[isra-fel]

Looks good to me. @wyunchi-ms could you help merge it? Thanks