Fixed public_deps for libjingle_peerconnection{,_api}

https://codereview.webrtc.org/2514883002/ changed and moved these targets around but did not add public dependencies for the fallbacks, which causes gn gen --check a lot of anger.

NOTRY=true # Only build changes and windows bots are cranky atm.
BUG=webrtc:5806

Review-Url: https://codereview.webrtc.org/2651663002
Cr-Commit-Position: refs/heads/master@{#16214}

webrtc/api/BUILD.gn

@@ -88,7 +88,7 @@ rtc_static_library("libjingle_peerconnection_api") {
 
 # TODO(ossu): Remove once downstream projects have updated.
 rtc_source_set("libjingle_peerconnection") {
-  deps = [
+  public_deps = [
     "../pc:libjingle_peerconnection",
   ]
 }

webrtc/pc/BUILD.gn

@@ -146,13 +146,16 @@ rtc_static_library("libjingle_peerconnection") {
   deps = [
     ":rtc_pc",
     "../api:call_api",
-    "../api:libjingle_peerconnection_api",
     "../api:rtc_stats_api",
     "../call",
     "../media",
     "../stats",
   ]
 
+  public_deps = [
+    "../api:libjingle_peerconnection_api",
+  ]
+
   if (rtc_use_quic) {
     sources += [
       "quicdatachannel.cc",