Explicitly initialise base class in copy constructor

Fixes:
In file included from frameworks/av/media/libmedia/include/media/IMediaPlayer.h:27:0,
                 from frameworks/av/media/libmedia/include/media/IMediaPlayerService.h:29,
                 from frameworks/av/media/libmedia/include/media/IMediaDeathNotifier.h:21,
                 from hardware/qcom/display/msm8994/libhwcomposer/hwc_qclient.h:37,
                 from hardware/qcom/display/msm8994/libhwcomposer/hwc_utils.cpp:41:
frameworks/av/include/media/VolumeShaper.h: In copy constructor 'android::media::VolumeShaper::Configuration::Configuration(const
android::media::VolumeShaper::Configuration&)':
frameworks/av/include/media/VolumeShaper.h:135:18: error: base class 'class android::Parcelable' should be explicitly initialized in the copy constructor
[-Werror=extra]
         explicit Configuration(const Configuration &configuration)
                  ^
cc1plus: all warnings being treated as errors

Change-Id: I37b77d21bc625355309a634520153c2b9d6332c8