AudioPolicyService: Fix mutex ordering issue

        AudioDeviceTypeAddrVector devices;

        bool hasSpatializer = mAudioPolicyManager->canBeSpatialized(&attr, nullptr, devices);

        if (hasSpatializer) {

            // Unlock as Spatializer::create() will use the callback and acquire the

            // AudioPolicyService_Mutex.

            mLock.unlock();

            mSpatializer = Spatializer::create(this, effectsFactoryHal);

            mLock.lock();

        }

        if (mSpatializer == nullptr) {

            // No spatializer created, signal the reason: NO_INIT a failure, OK means intended.