Add privacy configuration option to collect full IP in mobile monitoring

Background and context

Users IP are masked/anonymized by default in mobile monitoring (EUM/RUM) by setting the last octet of an IPv4 address to 0.

https://www.ibm.com/docs/en/instana-observability/current?topic=monitoring-mobile-app-faq#are-you-anonymizing-ips

In addition to this it's possible to set even stricter privacy rules in the Mobile App configuration. (See attached screenshot).

However, there's no option to disable the masking of an IP and collect the full IP.

Reasons for allowing the collection of an IP

There are two possible arguments to allow the collection of an IP while still being compliant to GDPR.

1: It's not personal data if it's not associated with a real person.

An IP is just an IP and is not by default associated to any real person, only to the device that the person is using. The IP could be shared, and in most cases it's dynamic and changes based on location or session, so there's no accurate way to identify a person with only the data collected by default in Instana.

2: It's OK to collect personal data as long as the rules are followed.

Instana already provides an option to collect personal data by adding user id, user name and user email as additional data points to the SDK collection.

https://www.ibm.com/docs/en/instana-observability/current?topic=monitoring-ios-api#identifying-users

With the warning "Please be aware of the respective data protection laws when choosing to do so.".

In this case Instana provides the option for the user (us) to collect the personal data information as long as we comply to privacy laws. This is something we can do, for example by informing users/asking for consent from users.

So with the argument that it's ok to collect personal data in one case, by choice of the customer (us), it should be OK by Instana to also allow collection of the full IP by choice of the customer.

Why we need it

One specific case where we need the real IP is to understand how many calls that the mobile app generates from an IP at most. This is in order to be able to set reasonable rate limits on the backend without impacting real users. Rate limits are an important tool to reduce misuse of the backend API by malicious actors. While we know the app behaviour well, a dynamic factor is shared IP's such as from hotel/café wifi's that we cannot guess but have to rely on monitoring.

Another specific case is that it helps in testing/troubleshooting scenarios.