The exception says nothing about private corporations or indivduals. If it's owned by the government or leased by the government, and not otherwise a prohibited place, then 30.06 doesn't apply. It's right there in black and white.But does "owned by a governmental entity" supercede "leased by a private corporation?"
It is an exception to the application of this section that the property on which the license holder carries a handgun is owned or leased by a governmental entity and is not a premises or other place on which the license holder is prohibited from carrying the handgun under Section 46.03 or 46.035.