RANGER-5435: Change the default KMS ZoneKey length from 128 to 256

[vikaskr22]

What changes were proposed in this pull request?

For KMS ZoneKey, this PR makes the key length to be 256 by default.
It still respects the user provided keyLength, like 128, 192 . But if user doesn't provide any input, it will default to 256. On KeyAdmin create key UI, 256 will be rendered as default keyLength.
Also, 0 is a valid keyLength. It means, user wants to use the Encryption algorithm's default keySize. And this depends on the underlying SecurityProvider.

Note: If user creates key using hadoop key create cli command, then by default it gets the keyLength from their core-site.xml file and it is 128 there. Also 128 is defined as the default value there. So in this case, Ranger receives request with keyLength as 128 and it will create the key of 128 length only.

To avoid this, users can update the following prop in Hadoop's core-site.xml :

Key : hadoop.security.key.default.bitlength
Value : 256

How was this patch tested?

• mvn build
• UTs
• Tested following cases on internal cluster:
  ZoneKey creation from keyAdmin UI with empty keyLength, 0 keyLength, user provided keyLength.
  ZoneKey creation using RangerAdmin Rest API
  ZoneKey creation using KMS Rest endpoint directly.
  Hadoop cli command