change toLowerCase() to lowercase() (#351)

Author: mozzius

android/src/main/java/com/reactnativecompressor/Audio/AudioHelper.kt

@@ -58,7 +58,7 @@ class AudioHelper {
       var destinationBitrate = originalBitrate
       Utils.addLog("source bitrate: $originalBitrate")
 
-      when (quality.toLowerCase()) {
+      when (quality.lowercase()) {
         "low" -> destinationBitrate = maxOf(64, (originalBitrate * 0.3).toInt())
         "medium" -> destinationBitrate = (originalBitrate * 0.5).toInt()
         "high" -> destinationBitrate = minOf(320, (originalBitrate * 0.7).toInt())

android/src/main/java/com/reactnativecompressor/Utils/Uploader.kt

@@ -161,7 +161,7 @@ class Uploader(private val reactContext: ReactApplicationContext) {
     if (mimeType == null) {
       val fileExtension = MimeTypeMap.getFileExtensionFromUrl(fileUri.toString())
       if (fileExtension != null) {
-        return MimeTypeMap.getSingleton().getMimeTypeFromExtension(fileExtension.toLowerCase())
+        return MimeTypeMap.getSingleton().getMimeTypeFromExtension(fileExtension.lowercase())
       }
     }