Merge "Improve MediaButtonReceiverHolder toString()"

    @Override

    public String toString() {

        if (mPendingIntent != null) {

            return "MBR {pi=" + mPendingIntent + ", type=" + mComponentType + "}";

        }

        return "Restored MBR {component=" + mComponentName + ", type=" + mComponentType + "}";

        StringBuilder sb = new StringBuilder();

        sb.append("MBR {pi=").append(mPendingIntent);

        sb.append(", componentName=").append(mComponentName);

        sb.append(", type=").append(mComponentType);

        sb.append(", pkg=").append(mPackageName);

        sb.append("}");

        return sb.toString();

    }

    /**