Change config namespace as dataSources

[niveathika]

Purpose

$subject

# Datasource Configurations
dataSources:
  - name: WSO2_PERMISSIONS_DB
    description: The datasource used for permission feature
    jndiConfig:
      name: jdbc/PERMISSION_DB
      useJndiReference: true
    definition:
      type: RDBMS
      configuration:
        jdbcUrl: 'jdbc:h2:${sys:carbon.home}/wso2/${sys:wso2.runtime}/database/PERMISSION_DB;IFEXISTS=TRUE;DB_CLOSE_ON_EXIT=FALSE;LOCK_TIMEOUT=60000;MVCC=TRUE'
        username: wso2carbon
        password: wso2carbon
        driverClassName: org.h2.Driver
        maxPoolSize: 10
        idleTimeout: 60000
        connectionTestQuery: SELECT 1
        validationTimeout: 30000
        isAutoCommit: false

Goals

Streamline config as discussed in https://groups.google.com/forum/?hl=en#!topic/siddhi-dev/j3W4mA8jjQ8 part of the task list in siddhi-io/distribution#263

Approach

As in 48d9e51

Documentation

N/A as it is backward compatible

Automation tests

• Unit tests - Attached herewith
• Integration tests - N/A

Security checks

• Followed secure coding standards in http://wso2.com/technical-reports/wso2-secure-engineering-guidelines? yes
• Ran FindSecurityBugs plugin and verified report? yes
• Confirmed that this PR doesn't commit any keys, passwords, tokens, usernames, or other secrets? yes