Issues - Mixed stacktraces not displayed nicely Java + Native

### Problem Statement

This one is actually symbolicated but we just don't display a mixed stacktrace nicely (java + native). All the unknown frames are supposed to be Java frames and have a different view

### Solution Brainstorm

_No response_

### Product Area

Issues

Start from the mixed Java and native stacktrace shown in the issue image and inspect how unknown frames are rendered in the Issues product. Confirm the expected behavior for symbolicated traces: unknown frames should use the Java-frame view and the complete mixed stacktrace should display clearly.

Written by the indexing model from the issue text.