paygen_build_lib: Remove excessive flags controlling payloads.

Remove these unused control flags:
  skip_full_payloads
  skip_test_payloads
  skip_nontest_payloads

Keep this flag:
  skip_delta_payloads

BUG=None
TEST=None

Change-Id: I6efb1e7e7a3a34369a78ce78a6fa5a5bfef1614f
Reviewed-on: https://chromium-review.googlesource.com/346726
Commit-Ready: Don Garrett <dgarrett@chromium.org>
Tested-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
2 files changed