@uppy/audio: move internal property to private field

[aduh95]

No description provided.

[github-actions]

Diff output files

diff --git a/packages/@uppy/audio/lib/Audio.js b/packages/@uppy/audio/lib/Audio.js
index 63df9da..999ffb3 100644
--- a/packages/@uppy/audio/lib/Audio.js
+++ b/packages/@uppy/audio/lib/Audio.js
@@ -28,6 +28,7 @@ import supportsMediaRecorder from "./supportsMediaRecorder.js";
 const packageJson = {
   "version": "2.0.0-beta.5",
 };
+var _recordingLengthTimer = _classPrivateFieldLooseKey("recordingLengthTimer");
 var _stream = _classPrivateFieldLooseKey("stream");
 var _audioActive = _classPrivateFieldLooseKey("audioActive");
 var _recordingChunks = _classPrivateFieldLooseKey("recordingChunks");
@@ -54,6 +55,10 @@ export default class Audio extends UIPlugin {
     Object.defineProperty(this, _hasAudioCheck, {
       value: _hasAudioCheck2,
     });
+    Object.defineProperty(this, _recordingLengthTimer, {
+      writable: true,
+      value: void 0,
+    });
     Object.defineProperty(this, _stream, {
       writable: true,
       value: null,
@@ -155,7 +160,7 @@ export default class Audio extends UIPlugin {
           }
         });
         _classPrivateFieldLooseBase(this, _recorder)[_recorder].start(500);
-        this.recordingLengthTimer = setInterval(() => {
+        _classPrivateFieldLooseBase(this, _recordingLengthTimer)[_recordingLengthTimer] = setInterval(() => {
           const currentRecordingLength = this.getPluginState().recordingLengthSeconds;
           this.setPluginState({
             recordingLengthSeconds: currentRecordingLength + 1,
@@ -174,7 +179,7 @@ export default class Audio extends UIPlugin {
             resolve();
           });
           _classPrivateFieldLooseBase(this, _recorder)[_recorder].stop();
-          clearInterval(this.recordingLengthTimer);
+          clearInterval(_classPrivateFieldLooseBase(this, _recordingLengthTimer)[_recordingLengthTimer]);
           this.setPluginState({
             recordingLengthSeconds: 0,
           });
@@ -241,7 +246,7 @@ export default class Audio extends UIPlugin {
               once: true,
             });
             _classPrivateFieldLooseBase(this, _recorder)[_recorder].stop();
-            clearInterval(this.recordingLengthTimer);
+            clearInterval(_classPrivateFieldLooseBase(this, _recordingLengthTimer)[_recordingLengthTimer]);
           });
         }
         _classPrivateFieldLooseBase(this, _recordingChunks)[_recordingChunks] = null;