Adding thread checker for audio record on native APIs

Implemented thread safety checks in WebRtcAudioRecord.java using ThreadUtils.ThreadChecker, matching the pattern in WebRtcAudioTrack.java. The checker is detached in the constructor and guards @CalledByNative control APIs (initRecording, startRecording, stopRecording, enableBuiltInAEC, enableBuiltInNS) to ensure they are called consistently from the same C++ worker thread. To prevent crashes, Java-only public APIs (such as setPreferredDevice and setMicrophoneMute) and read-only query APIs remain unguarded as they are expected to be called from application or stats threads.

Bug: webrtc:524395191
Change-Id: I432b9f6f8da1ead5e3ff021dfef4c6e12ef6557f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/484740
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Tim Na <natim@google.com>
Cr-Commit-Position: refs/heads/main@{#48068}