Don't leak MediaFileHandle when downloading voice messages (#1748)

Uses the new `MediaFile.persist()` [API](https://github.com/matrix-org/matrix-rust-sdk/pull/2789) to cache voice messages.
This allows to close the `MediaFile` handle after use and keeping the file.
Also disables rust sdk caching for voice messages as we'll use the app's cache dir for that purpose.

Fixes: https://github.com/vector-im/element-meta/issues/2175

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/media/MatrixMediaLoader.kt

@@ -35,7 +35,13 @@ interface MatrixMediaLoader {
      * @param source to fetch the data for.
      * @param mimeType: optional mime type.
      * @param body: optional body which will be used to name the file.
+     * @param useCache: if true, the rust sdk will cache the media in its store.
      * @return a [Result] of [MediaFile]
      */
-    suspend fun downloadMediaFile(source: MediaSource, mimeType: String?, body: String?): Result<MediaFile>
+    suspend fun downloadMediaFile(
+        source: MediaSource,
+        mimeType: String?,
+        body: String?,
+        useCache: Boolean = true,
+    ): Result<MediaFile>
 }

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/media/MediaFile.kt

@@ -21,10 +21,16 @@ import java.io.File
 
 /**
  * A wrapper around a media file on the disk.
- * When closed the file will be removed from the disk.
+ * When closed the file will be removed from the disk unless [persist] has been used.
  */
 interface MediaFile : Closeable {
     fun path(): String
+
+    /**
+     * Persists the temp file to the given path. The file will be moved to
+     * the given path and won't be deleted anymore when closing the handle.
+     */
+    fun persist(path: String): Boolean
 }
 
 fun MediaFile.toFile(): File {