Fix wrong durations for uploaded media

At some point Uniffi introduced [automatic conversions](https://github.com/mozilla/uniffi-rs/blob/35140607dce7092f04d619a5d0b07f9ffe98b4ff/uniffi_bindgen/src/bindings/swift/templates/DurationHelper.swift#L19) from Rust's `Duration` to `TimeInterval`s but the original implementation for media uploading was using milliseconds. When the conversion happened there were no breaking changes and iOS kept sending millis instead of seconds, resulting in **very** wrong values.

ElementX/Sources/Services/Media/MediaUploadingPreprocessor.swift

@@ -77,7 +77,7 @@ private struct VideoProcessingInfo {
     let url: URL
     let height: Double
     let width: Double
-    let duration: Double
+    let duration: Double // seconds
     let mimeType: String
 }
 
@@ -213,7 +213,7 @@ struct MediaUploadingPreprocessor {
             return .failure(.failedProcessingAudio)
         }
 
-        let audioInfo = AudioInfo(duration: durationInSeconds * 1000, size: fileSize, mimetype: mimeType)
+        let audioInfo = AudioInfo(duration: durationInSeconds, size: fileSize, mimetype: mimeType)
         return .success(.audio(audioURL: url, audioInfo: audioInfo))
     }
 
@@ -413,7 +413,7 @@ struct MediaUploadingPreprocessor {
                 return .success(.init(url: newOutputURL,
                                       height: adjustedNaturalSize.height,
                                       width: adjustedNaturalSize.width,
-                                      duration: durationInSeconds * 1000,
+                                      duration: durationInSeconds,
                                       mimeType: "video/mp4"))
             } catch {
                 return .failure(.failedConvertingVideo)