Integration tests for custom properties

[rishikunnath2747]

Describe your changes

This PR adds integration tests for custom properties and removes some redundant test cases

Test cases (Ran on develop)

1. Should update valid properties of attachments during create of entity
2. Should update valid properties of attachments after save of entity
3. Should not update invalid properties of attachments and should update valid properties during create of entity
4. Should not update invalid properties of attachments and should update valid properties after save of entity

Any documentation

Test cases added to wiki

Type of change

Adding test cases

Checklist before requesting a review

• I have tested the functionality on my cloud environment.
• I have provided sufficient automated/ unit tests for the code.
• I have increased or maintained the test coverage.
• I have ran integration tests on my cloud environment.
• I have validated blackduck portal for any vulnerability after my commit.

Upload Screenshots/lists of the scenarios tested

• I have Uploaded Screenshots or added lists of the scenarios tested in description