build: clean up api/BUILD.gn

using
  xargs tools_webrtc/gn_check_autofix.py -r api/BUILD.gn
followed by
  tools_webrtc/gn_check_autofix -C out/Default

The removal of the "call" dep from the "enable_media" target
and "stats/rtcstats" from the "create_modular_peer_connection_factory"
targets were reverted due to linker failures.

Changes to the libjingle_peerconnection legacy target were reverted.

Bug: webrtc:467294026
Change-Id: Iac9c6b0bdac23cfd5441bd0d9968202c15f70b1e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/455821
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Commit-Queue: Philipp Hancke <philipp.hancke@googlemail.com>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47126}