MediaButtonReceiver component may not be null.

[asugar]

Fatal Exception: java.lang.RuntimeException Unable to create service com.lzx.starrysky.MusicService: java.lang.IllegalArgumentException: MediaButtonReceiver component may not be null.

目前只有android4.4.4版本有此问题，

问题原因是：MediaButtonReceiver下的getMediaButtonReceiverComponent返回了null

1）在manifest中有MediaButtonReceiver的注册：

<receiver android:name="android.support.v4.media.session.MediaButtonReceiver">
            <intent-filter>
                <action android:name="android.intent.action.MEDIA_BUTTON" />
            </intent-filter>
        </receiver>

2）目前工程升级了androidx

[asugar]

<receiver android:name="androidx.media.session.MediaButtonReceiver" >
            <intent-filter>
                <action android:name="android.intent.action.MEDIA_BUTTON" />
            </intent-filter>
        </receiver>

[EspoirX]

已fix