Adding UNKNOWN value to Job constraint change enum.

Proto best practices are to have the first value in an enum be similar
to UNKNOWN/UNSET/NONE.

Bug: 120941744
Bug: 120793892
Test: Android builds
Change-Id: I8a764565d14ad6dde93ebfcbd55fd37cf533b253
1 file changed
tree: b0295b2f2d2da2110eeba7ba5e913a97b2f6b5bd
  1. atom_field_options.proto
  2. atoms.proto