[TIMOB-26501] Android: Add "cache" property support to HTTPClient

*Summary:* On iOS, HTTPClient supports boolean "cache" property, which can be set false to force HTTPClient to ignore the cache and always send the HTTP request. https://docs.appcelerator.com/platform/latest/#!/api/Titanium.Network.HTTPClient-property-cache Android does not currently support this property and always uses the cache. We should add support for this property so the cache can be ignored on Android too. *Note:* We need to evaluate if a POST request should be cached at all. I think no, but we should double check how it works on iOS when setting this property true.