Fix policy view interface loading issue

[madawas]

Purpose

When the policy view page is loaded some of the variables of the policyPayloadObj becomes undefined or null. This commit checks for the empty and undefined variables.

Related to wso2/product-iots#1681

Goals

Fixing the policy UI not loading issue

Approach

Checking for null and empty values in possible places

User stories

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Release note

Fix policy view interface loading issue

Documentation

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Training

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Certification

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Marketing

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Automation tests

• Unit tests

  Code coverage information

• Integration tests

  Details about the test cases and coverage

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

Samples

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Related PRs

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Migrations (if applicable)

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Test environment

JDK 1.8.0_161, Ubuntu 16.04, H2, Chrome latest

Learning

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