Reland "Move injection of PacketSocketFactory from PC to PCF"

This is a reland of commit 905c3a6c73d293882ef11942066ccda52a9e14d1

Change from previous attempt is between ps#1 and ps#2: Use PeerConnectionFactoryInterface::Options to clear the `network_ignore_mask`.

Original change's description:
> Move injection of PacketSocketFactory from PC to PCF
>
> Injection via PeerConnectionDependecies was broken, in not accepting
> ownership of the injected object.
>
> Bug: webrtc:7447, webrtc:14204
> Change-Id: Ic53f05d51928b006fc1e46d502633d88471eb518
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/266140
> Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#37270}

Bug: webrtc:7447, webrtc:14204
Change-Id: Ic78ebec2e88a8c44699015c8c7a44e137f44253a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/265982
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37290}
diff --git a/api/BUILD.gn b/api/BUILD.gn
index 5f6bc49..cd1c104 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -1100,6 +1100,17 @@
     ]
   }
 
+  rtc_source_set("mock_packet_socket_factory") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [ "test/mock_packet_socket_factory.h" ]
+
+    deps = [
+      ":packet_socket_factory",
+      "../test:test_support",
+    ]
+  }
+
   rtc_source_set("mock_peerconnectioninterface") {
     visibility = [ "*" ]
     testonly = true
@@ -1322,6 +1333,7 @@
       ":mock_frame_decryptor",
       ":mock_frame_encryptor",
       ":mock_media_stream_interface",
+      ":mock_packet_socket_factory",
       ":mock_peer_connection_factory_interface",
       ":mock_peerconnectioninterface",
       ":mock_rtp",