fix(core): [Session based Traces for Mobile 1] Keep spanless baggage mutable#5384

adinauer wants to merge 2 commits intofeat/session-based-traces-mobilegetsentry/sentry-java:feat/session-based-traces-mobilefrom

fix/session-based-traces-mobile-baggage-freezegetsentry/sentry-java:fix/session-based-traces-mobile-baggage-freezeCopy head branch name to clipboard