Revert "Added zeroMaterial configurations for Phase II tracker"

This reverts commit 4b289fc93c1454130b3d28e748f09ce97b160a4f.
Added modified tracker.xml from Sebastien Viret that replaces module material by air
Synchronize tracker_AIR.xml with the version in CMSSW_6_2_0_SLHC12_patch1