Fetch Google netblock from JSON on gstatic domain

[modular-magician]

Release Note Template for Downstream PRs (will be copied)

netblock: fixed the google netblock ranges returned by the `google_netblock_ip_ranges` by targeting json on gstatic domain instead of reading SPF dns records (solution provided by network team)

We experienced the issue after seeing that some google domains are outside of the IPs provided by the SPF records.
For example :

ig datastudio.google.com
; <<>> DiG 9.10.6 <<>> datastudio.google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39814
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;datastudio.google.com.		IN	A
;; ANSWER SECTION:
datastudio.google.com.	299	IN	A	142.250.31.101
datastudio.google.com.	299	IN	A	142.250.31.102
datastudio.google.com.	299	IN	A	142.250.31.138
datastudio.google.com.	299	IN	A	142.250.31.113
datastudio.google.com.	299	IN	A	142.250.31.100
datastudio.google.com.	299	IN	A	142.250.31.139
;; Query time: 96 msec
;; SERVER: 10.114.228.14#53(10.114.228.14)
;; WHEN: Fri Jun 12 11:33:54 CEST 2020
;; MSG SIZE  rcvd: 146

Currently the datasource return:

data.google_netblock_ip_ranges.netblock: Refreshing state...

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.

Outputs:

cidr_blocks = [
  "35.190.247.0/24",
  "64.233.160.0/19",
  "66.102.0.0/20",
  "66.249.80.0/20",
  "72.14.192.0/18",
  "74.125.0.0/16",
  "108.177.8.0/21",
  "173.194.0.0/16",
  "209.85.128.0/17",
  "216.58.192.0/19",
  "216.239.32.0/19",
  "2001:4860:4000::/36",
  "2404:6800:4000::/36",
  "2607:f8b0:4000::/36",
  "2800:3f0:4000::/36",
  "2a00:1450:4000::/36",
  "2c0f:fb50:4000::/36",
  "172.217.0.0/19",
  "172.217.32.0/20",
  "172.217.128.0/19",
  "172.217.160.0/20",
  "172.217.192.0/19",
  "172.253.56.0/21",
  "172.253.112.0/20",
  "108.177.96.0/19",
  "35.191.0.0/16",
  "130.211.0.0/22",
]

With the changes proposed it return:

data.google_netblock_ip_ranges.netblock: Refreshing state...

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.

Outputs:

cidr_blocks = [
  "8.8.4.0/24",
  "8.8.8.0/24",
  "8.34.208.0/20",
  "8.35.192.0/20",
  "23.236.48.0/20",
  "23.251.128.0/19",
  "34.64.0.0/10",
  "35.184.0.0/13",
  "35.192.0.0/14",
  "35.196.0.0/15",
  "35.198.0.0/16",
  "35.199.0.0/17",
  "35.199.128.0/18",
  "35.200.0.0/13",
  "35.208.0.0/12",
  "35.224.0.0/12",
  "35.240.0.0/13",
  "64.15.112.0/20",
  "64.233.160.0/19",
  "66.102.0.0/20",
  "66.249.64.0/19",
  "70.32.128.0/19",
  "72.14.192.0/18",
  "74.114.24.0/21",
  "74.125.0.0/16",
  "104.154.0.0/15",
  "104.196.0.0/14",
  "104.237.160.0/19",
  "107.167.160.0/19",
  "107.178.192.0/18",
  "108.59.80.0/20",
  "108.170.192.0/18",
  "108.177.0.0/17",
  "130.211.0.0/16",
  "136.112.0.0/12",
  "142.250.0.0/15",
  "146.148.0.0/17",
  "162.216.148.0/22",
  "162.222.176.0/21",
  "172.110.32.0/21",
  "172.217.0.0/16",
  "172.253.0.0/16",
  "173.194.0.0/16",
  "173.255.112.0/20",
  "192.158.28.0/22",
  "192.178.0.0/15",
  "199.36.154.0/23",
  "199.36.156.0/24",
  "199.192.112.0/22",
  "199.223.232.0/21",
  "207.223.160.0/20",
  "208.65.152.0/22",
  "208.68.108.0/22",
  "208.81.188.0/22",
  "208.117.224.0/19",
  "209.85.128.0/17",
  "216.58.192.0/19",
  "216.73.80.0/20",
  "216.239.32.0/19",
  "2001:4860::/32",
  "2404:6800::/32",
  "2404:f340::/32",
  "2600:1900::/28",
  "2607:f8b0::/32",
  "2620:11a:a000::/40",
  "2620:120:e000::/40",
  "2800:3f0::/32",
  "2a00:1450::/32",
  "2c0f:fb50::/32",
]

The solution has been provided by the GCP support (networking team).

Derived from GoogleCloudPlatform/magic-modules#3689