Android App wants Access to "/Data" Folder

Question

I want to stream AAC encoded audio Data from my Raspberry to my Android Phone. The part of receiving the data works well but there are some problems with decoding it.

I use Media Extractor and Media Codec to decode the audio data. Here is the important part of the code:

MediaExtractor extractor = new MediaExtractor();
Uri path = Uri.fromFile(file);

extractor.setDataSource(path.toString());

format = extractor.getTrackFormat(0); 
    String mime = format.getString(MediaFormat.KEY_MIME); 
    decoder = MediaCodec.createDecoderByType(mime); 
    decoder.configure(format, null, null, 0); 


    while (!stopTrack) { 


        multicastSocket.receive(packet); 

        decoder.start(); 
        data = packet.getData(); 

        inputBuffers = decoder.getInputBuffers(); 
        outputBuffers = decoder.getOutputBuffers(); 
        inputBufferIndex = decoder.dequeueInputBuffer(-1); 

        if (inputBufferIndex >= 0) 
        { 
            inputBuffer = inputBuffers[inputBufferIndex]; 
            inputBuffer.clear(); 

            inputBuffer.put(data); 

            decoder.queueInputBuffer(inputBufferIndex, 0, data.length, 0, 0); 
        } 

        bufferInfo = new MediaCodec.BufferInfo(); 
        outputBufferIndex = decoder.dequeueOutputBuffer(bufferInfo, 0); 

        while (outputBufferIndex >= 0) 
        { 
            outputBuffer = outputBuffers[outputBufferIndex]; 

            outputBuffer.position(bufferInfo.offset); 
            outputBuffer.limit(bufferInfo.offset + bufferInfo.size); 

            outData = new byte[bufferInfo.size]; 
            outputBuffer.get(outData); 

            //  Log.d("AudioDecoder", outData.length + " bytes decoded"); 

           track.write(outData, 0, outData.length); 

            decoder.releaseOutputBuffer(outputBufferIndex, false); 
            outputBufferIndex = decoder.dequeueOutputBuffer(bufferInfo, 0); 

        } 

These are the error messages I receive in the logcat:

D/ExtendedUtils: Try creating ExtendedExtractor 
E/MM_OSAL: FileSource::FileSource 
E/MM_OSAL: FileSource::FileSource m_bEveryThingOK 1 
E/MM_OSAL: MM_File_Create File Name /data/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: MM_File_Create failed .Efs Error No -1 , File Name      /data/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: Open or read fail on /data/mmosal_logmask.cfg. Possible permission denied issue. Looking for /data/misc/media/mmosal_logmask.cfg 
E/MM_OSAL: MM_File_Create File Name /data/misc/media/mmosal_logmask.cfg , Mode 0  
E/MM_OSAL: MM_File_Create failed .Efs Error No -1 , File Name /data/misc/media/mmosal_logmask.cfg , Mode 0 
E/MMParserExtractor:  FileSourceWrapper::New returned NULL 
D/ExtendedUtils: default extractor is NULL, return extended extractor 
E/MM_OSAL: FileSource::FileSource 
E/MM_OSAL: FileSource::FileSource m_bEveryThingOK 1 
E/MM_OSAL: MM_File_Create File Name /data/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: MM_File_Create failed .Efs Error No -1 , File Name /data/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: Open or read fail on /data/mmosal_logmask.cfg. Possible permission denied issue. Looking for /data/misc/media/mmosal_logmask.cfg 
E/MM_OSAL: MM_File_Create File Name /data/misc/media/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: MM_File_Create failed .Efs Error No -1 , File Name /data/misc/media/mmosal_logmask.cfg , Mode 0 
E/MM_OSAL: parseTransportStreamPacket isPESPacket failed 18954 
E/MM_OSAL: parseTransportStreamPacket isPESPacket failed 18783 
E/MM_OSAL: parseTransportStreamPacket isPESPacket failed 18954 
E/MM_OSAL: parseTransportStreamPacket isPESPacket failed 18783 
I/OMXClient: Using client-side OMX mux. 
E/OMXMaster: A component of name 'OMX.qcom.audio.decoder.aac' already exists, ignoring this one. 
D/MediaCodec: MediaCodec[kWhatConfigure]: video-output-protection: 00000000, audio-output-protection: 00000000 
E/Format:: audio/mp4a-latm 
W/SoftAAC2: aacDecoder_DecodeFrame decoderErr = 0x4004 
W/SoftAAC2: AAC decoder returned error 0x4004, substituting silence 
I/SoftAAC2: Reconfiguring decoder: 0->44100 Hz, 0->0 channels 

What is MM_OSAL and why does it want to create a file in the "/data" folder on my phone? I searched for it and found out that you need root rights to have access to this folder. I debug the app with android studio directly connected with my phone over USB, is this a problem?

Thanks for any help!