Pass `enableBotFiltering = false` unless explicitly set

[karnowski]

Background

Adzerk has the ability to enable/disable bot filtering per ad request. Basically, if the ad request is coming from a web browser then the user agent will look valid, and the bot filtering feature should be enabled. However, if a customer is making an ad request from a mobile app then the bot filtering feature should be disabled. Otherwise the user agent will be that of the SDK or programming language, may look invalid against the bot allow list, and could be incorrectly discarded in reporting.

For our mobile SDKs, we should default the enableBotFiltering ad request setting to false.

Acceptance Criteria

In the iOS SDK:

• Ensure the enableBotFiltering decision request parameter defaults as to false.
• Allow the integrating developer to optionally pass a boolean value of their own for enableBotFiltering.