Use MimeTypes object instead of hard-coded strings.

libraries/voicerecorder/test/build.gradle.kts

@@ -28,4 +28,5 @@ dependencies {
 
     implementation(libs.coroutines.test)
     implementation(libs.test.truth)
+    implementation(projects.libraries.core)
 }

libraries/voicerecorder/test/src/main/kotlin/io/element/android/libraries/voicerecorder/test/FakeVoiceRecorder.kt

@@ -17,6 +17,7 @@
 package io.element.android.libraries.voicerecorder.test
 
 import com.google.common.truth.Truth.assertThat
+import io.element.android.libraries.core.mimetype.MimeTypes
 import io.element.android.libraries.voicerecorder.api.VoiceRecorder
 import io.element.android.libraries.voicerecorder.api.VoiceRecorderState
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -73,7 +74,7 @@ class FakeVoiceRecorder(
                 null -> VoiceRecorderState.Idle
                 else -> VoiceRecorderState.Finished(
                     file = curRecording!!,
-                    mimeType = "audio/ogg",
+                    mimeType = MimeTypes.Ogg,
                     duration = recordingDuration,
                     waveform = waveform,
                 )