Expose Custom Buffer Duration for Error-triggered Replays

### Problem Statement

Currently, the Sentry Mobile SDK buffers replay data before an error occurs when `onErrorSampleRate` is enabled. However, the duration of this pre-error buffer is not configurable by customers and is limited to 1 minute as detailed [here](https://docs.sentry.io/platforms/flutter/session-replay/#sampling). Some users have expressed interest in adjusting this buffer period to capture more context leading up to an error.

### Solution Brainstorm

Expose a configurable option in the SDKs to allow users to set the buffer duration for error-triggered session replays.

**Concerns to address:**
- If the buffer is over 1 minute, it could consume more device resources to create a longer video segment
- The replay could be rejected due to size limitations

### Are you willing to submit a PR?

None