RUM - define debug mode

[Kielek]

Is your feature request related to a problem? Please describe.

Both ios and android defines debug mode functionality. It is not documented in gdi-spec.

Describe the solution you'd like
Common way to define span filtering for:

• enableDebug() https://docs.splunk.com/observability/en/gdi/get-data-in/rum/android/configure-rum-android-instrumentation.html
• debug https://docs.splunk.com/observability/en/gdi/get-data-in/rum/ios/configure-rum-ios-instrumentation.html#general-settings

Describe alternatives you've considered
N/A

Additional context
Review for #255