Camera doesn't start on arm64 - crash in AalServicePlugin::devices(QByteArray const&)

Camera crashes on startup on arm64

It's possible the reason is the lack of media-hub (bug #1618416), but camera should probably not die because of that.

$ system-image-cli -i
current build number: 23
device name: frieza_arm64
channel: ubuntu-touch/staging/ubuntu
last update: 2016-08-30 09:13:12
version version: 23
version ubuntu: 20160830
version device: 20160824.0
version custom: 20160830

Steps:
* flash the above channel (remember --device frieza_arm64)
* launch camera

== Logfile =================================
Loading module: 'libubuntu_application_api_touch_mirclient.so.3.0.0'
Import path added "/usr/share/click/preinstalled/com.ubuntu.camera/3.0.0.654/lib/aarch64-linux-gnu"
Camera app directory "/usr/share/click/preinstalled/com.ubuntu.camera/3.0.0.654"
virtual QMediaService* AalServicePlugin::create(const QString&) "org.qt-project.qt.mediaplayer"
[TT 2016-08-30 12:35:27.595951] [service.cpp:29@instance]
Failed to start a new media-hub player session: org.freedesktop.DBus.Error.ServiceUnknown: The name core.ubuntu.media.Service was not provided by any .service files
Failed to create a new media player backend. Video playback will not function.

Could not finish contructing new AalMediaPlayerService instance since m_hubPlayerSession is NULL
library "libcamera_compat_layer.so" not found

== Stacktrace =================================
#0 0x0000000000000000 in ()
#1 0x0000007f6d20b7e4 in AalServicePlugin::devices(QByteArray const&) const (this=<optimized out>, service=...) at aalcameraserviceplugin.cpp:56
        deviceList = {<QListSpecialMethods<QByteArray>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = -1}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7f87cc9d60 <QListData::shared_null>}, d = 0x7f87cc9d60 <QListData::shared_null>}}
        cameras = -293107960
#2 0x0000007f74ff8d8c in QPluginServiceProvider::devices(QByteArray const&) const (this=<optimized out>, serviceType=...) at qmediaserviceprovider.cpp:593
        obj = <optimized out>
        _container_ = {c = {<QListSpecialMethods<QObject*>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x39e32080}, d = 0x39e32080}}, i = {i = 0x39e32090}, e = {i = 0x39e320a0}, control = 1}
        res = {<QListSpecialMethods<QByteArray>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7f87cc9d60 <QListData::shared_null>}, d = 0x7f87cc9d60 <QListData::shared_null>}}
#3 0x0000007f75024a18 in QCameraInfo::availableCameras(QCamera::Position) (position=position@entry=QCamera::UnspecifiedPosition) at camera/qcamerainfo.cpp:242
        cameras = {<QListSpecialMethods<QCameraInfo>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7f87cc9d60 <QListData::shared_null>}, d = 0x7f87cc9d60 <QListData::shared_null>}}
        provider = 0x7f7508eda0 <(anonymous namespace)::Q_QGS_pluginProvider::innerFunction()::holder>
        service = {static MaxSize = 1073741800, d = 0x39e0eed0}
        devices = {<QListSpecialMethods<QByteArray>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7f87cc9d60 <QListData::shared_null>}, d = 0x7f87cc9d60 <QListData::shared_null>}}
#4 0x0000007f6d217d00 in AalVideoDeviceSelectorControl::deviceCount() const (this=<optimized out>) at aalvideodeviceselectorcontrol.cpp:45
#5 0x0000007f75023e68 in QCameraInfo::QCameraInfo(QCamera const&) (this=0x7fee878938, camera=...) at camera/qcamerainfo.cpp:99
        deviceControl = 0x39e30110
        infoControl = <optimized out>

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: camera-app 3.0.0+16.04.20160824-0ubuntu1 [origin: LP-PPA-ci-train-ppa-service-stable-phone-overlay]
Uname: Linux 3.10.93+ aarch64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: arm64
Date: Tue Aug 30 12:48:50 2016
SourcePackage: camera-app
UpgradeStatus: No upgrade log present (probably fresh install)