How do I use `awk` to count all lines adhering to the following structure:

```
"any-string" : "any-string"

```

For example

```
      "ssl.server.keystore.type" : 
      "mapred-logsearch-conf" : {
      "hive.server2.thrift.sasl.qop" : "auth",
      "hive.merge.orcfile.stripe.level" : "true",
      "hive.orc.splits.include.file.footer" : "false",
      "hive.exec.compress.output" : "false",
      "hive.user.install.directory" : "/user/",
      "hive.prewarm.enabled" : "false",
      "hive.compactor.delta.num.threshold" : "10",
      "hive.orc.compute.splits.num.threads" : "10",
      "hive.vectorized.groupby.checkinterval" : "4096",
      "properties_attributes" : { },

```

would produce the output "9".