core: Fix TestContext2Apply_issue7824
core: Fix TestContext2Apply_issue7824

This test was incorrectly amended on the first pass to create a
configuration snapshot from the step zero configuration, rather than the
step one configuration that the save plan is built from.

Along with that, it needed various other minor updates to match with
details that have shifted:
- "id" and "type" attributes must be explicitly declared in schema
- template_file.parent has count = 1, which now causes it to get an index
  and be a list where before it did not.

rnaveiras/terraform,luis-silva/terraform,iljaskevic/terraform,hashicorp/terraform,brandontosch/terraform,tpounds/terraform,VladRassokhin/terraform,ewbankkit/terraform,pradeepbhadani/terraform,apparentlymart/terraform,youhong316/terraform,nlamirault/terraform,heimweh/terraform,hashicorp/terraform,VladRassokhin/terraform,pdecat/terraform,drebes/terraform,ewbankkit/terraform,tommynsong/terraform,drebes/terraform,pdecat/terraform,mattray/terraform,luis-silva/terraform,drebes/terraform,VladRassokhin/terraform,pradeepbhadani/terraform,hashicorp/terraform,rnaveiras/terraform,mattray/terraform,youhong316/terraform,ewbankkit/terraform,heimweh/terraform,heimweh/terraform,brandontosch/terraform,apparentlymart/terraform,rnaveiras/terraform,ewbankkit/terraform,nlamirault/terraform,pradeepbhadani/terraform,iljaskevic/terraform,tpounds/terraform,mattray/terraform,mattray/terraform,pryorda/terraform,iljaskevic/terraform,pdecat/terraform,heimweh/terraform,apparentlymart/terraform,youhong316/terraform,brandontosch/terraform,tpounds/terraform,apparentlymart/terraform,nlamirault/terraform,youhong316/terraform,gechr/terraform,heimweh/terraform,drebes/terraform,iljaskevic/terraform,brandontosch/terraform,pdecat/terraform,tommynsong/terraform,pryorda/terraform,apparentlymart/terraform,tpounds/terraform,tommynsong/terraform,gechr/terraform,luis-silva/terraform,VladRassokhin/terraform,gechr/terraform,brandontosch/terraform,pryorda/terraform,luis-silva/terraform