[TIDOC-1988] add platform to gravity property
[TIDOC-1988] add platform to gravity property

mano-mykingdom/titanium_mobile,jhaynie/titanium_mobile,mano-mykingdom/titanium_mobile,mano-mykingdom/titanium_mobile,jhaynie/titanium_mobile,cheekiatng/titanium_mobile,jhaynie/titanium_mobile,ashcoding/titanium_mobile,jhaynie/titanium_mobile,jhaynie/titanium_mobile,mano-mykingdom/titanium_mobile,cheekiatng/titanium_mobile,ashcoding/titanium_mobile,mano-mykingdom/titanium_mobile,ashcoding/titanium_mobile,jhaynie/titanium_mobile,cheekiatng/titanium_mobile,ashcoding/titanium_mobile,mano-mykingdom/titanium_mobile,ashcoding/titanium_mobile,cheekiatng/titanium_mobile,jhaynie/titanium_mobile,jhaynie/titanium_mobile,cheekiatng/titanium_mobile,cheekiatng/titanium_mobile,ashcoding/titanium_mobile,ashcoding/titanium_mobile,mano-mykingdom/titanium_mobile,ashcoding/titanium_mobile,cheekiatng/titanium_mobile,mano-mykingdom/titanium_mobile,cheekiatng/titanium_mobile