change tracer index extent of ecosys_source_sink_3d to ecosys_ind extent

### Description of the issue:

will partially enable passing all blocks into ecosys_driver_set_interior without an argument copy

### Version:
- CESM: 2.2
- POP2: master
- Migrating from @klindsay28's [marbl-ecosys/MARBL#110](https://github.com/marbl-ecosys/MARBL/issues/110), originally noted in November, 2016

### Machine/Environment Description:

Machine independent

### Any xml/namelist changes or SourceMods:

Problem exists out of the box