Remove unnecessary spatial audio initialization

The initSADevice alters the spatial audio enabled property which should
only be called when a new device is connected. Having this in the
addCompatibleAudioDevice method will override the property selected by
the user

Test: manual & atest SpatializerHelperTest
Bug: 297341688
Change-Id: I6d2fdb5508cea8219055b07d18896ca76d0bf637