[Backport PRs] Adds preset contentRegistry for IngestProcessors #3281

[brianf-aws]

Following a code commit (#3281) these are the following Backport PRs that need to be fixed. They stem from code divergence from using HTTPHeaders that previous branches are unfamiliar with.

• The backport to 2.x : [REVIEWED] backport/backport-3281-to-2.x

• The backport to 2.18: [REVIEWED] backport/backport-3281-to-2.18

• The backport to 2.17: [TBA] backport/backport-3281-to-2.17

• The backport to 2.15 : [TBA] backport/backport-3281-to-2.15

• The backport to 2.16: [TBA] backport/backport-3281-to-2.16

Next Steps:

• [] Investigate how we can avoid tedious backports like these
  • Different branches have different implementations of spotless apply. e.g main will add new lines for a method with many arguments, while 2.x will flatten it to one line
  • Dependencies are different such as HTTPHeaders not being supported.
• Clean up local repo for these backports

git worktree remove .worktrees/backport-2.x && git worktree remove .worktrees/backport-2.18

• Consider future steps we can take to make this less tedious
  - In the backport conflict message add a apply spotless to reduce a commit to the backport PR

[pyek-bot]

I would suggest fixing it for 2.18 and then adding backport labels for that fix itself, maybe that will reduce some manual effort and repeat that if you have to fix another conflict