EXCLUSIVE : One of the biggest shows on television is relocating to Los Angeles with the biggest California tax credit for a series to date. CBS ‘ Tracker , starring Justin Hartley , will move from Vancouver, where the first three seasons were shot. Its studio 20th Television is currently locking down production facilities in and around L.A., with filming on Season 4 slated to begin in late June. While the relocation decision was just recently finalized, it had been in the works for awhile. It was telegraphed when the California Film Commission in March unveiled the latest round of TV tax credits to 16 new and returning series and pilots under the state’s $750 million incentives program. There was one relocating show on the list, code named “Untitled Disney Entertainment Television Project 13,” which was awarded an eye-popping $48M on $129M in qualified expenditures.…