fix(profiling): keep frame-level platform information when available in mixed stack traces (#68694)

Way back we added
[frame-level](https://github.com/getsentry/vroom/blob/main/internal/frame/frame.go#L42)
platform information in `vroom`, but we're not passing this information
down from `sentry`.

This will help us to distinguish between `js` and `cocoa` frames in
mixed stack traces scenarios (such as for react-native).

Author: viglia

src/sentry/profiles/task.py

@@ -148,6 +148,10 @@ def process_profile_task(
     if not _normalize_profile(profile, organization, project):
         return
 
+    # set platform information at frame-level
+    # only for those platforms that didn't go through symbolication
+    _set_frames_platform(profile)
+
     if "version" in profile:
         set_measurement("profile.samples.processed", len(profile["profile"]["samples"]))
         set_measurement("profile.stacks.processed", len(profile["profile"]["stacks"]))
@@ -637,7 +641,9 @@ def truncate_stack_needed(
             # This works since symbolicated_frames are in the same order
             # as raw_frames (except some frames are not sent).
             for frame_idx in symbolicated_frames_dict[symbolicated_frame_idx]:
-                new_frames.append(symbolicated_frames[frame_idx])
+                f = symbolicated_frames[frame_idx]
+                f["platform"] = platform
+                new_frames.append(f)
 
             # go to the next symbolicated frame result
             symbolicated_frame_idx += 1
@@ -1115,3 +1121,17 @@ def _calculate_duration_for_sample_format_v2(profile: Profile) -> int:
 
 def _calculate_duration_for_android_format(profile: Profile) -> int:
     return int(profile["duration_ns"] * 1e-6)
+
+
+def _set_frames_platform(profile: Profile):
+    if "version" in profile:
+        platform = profile["platform"]
+        if platform in ["javascript", "node", "cocoa"]:
+            # bail early because it was already set
+            return
+        for i, _ in enumerate(profile["profile"]["frames"]):
+            profile["profile"]["frames"]["platform"] = platform
+        return
+    elif profile["platform"] == "android":
+        for i, _ in enumerate(profile["profile"]["methods"]):
+            profile["profile"]["methods"][i] = "android"