Reland "Android: Generate JNI code for androidnetworkmonitor_jni"

This reverts commit 522c1bc6bb945d66bf77f175da48e1644d74511e.

Reason for revert: Reland with a temporary fix.

Original change's description:
> Revert "Android: Generate JNI code for androidnetworkmonitor_jni"
> 
> This reverts commit 768e1c0ea1f2077675df31915132a0557aca400e.
> 
> Reason for revert: Breaks AppRTCMobile.
> 
> Original change's description:
> > Android: Generate JNI code for androidnetworkmonitor_jni
> > 
> > Bug: webrtc:8278
> > Change-Id: I8447b2de5ec2610760f7112b6f86e54d94325322
> > Reviewed-on: https://webrtc-review.googlesource.com/24520
> > Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> > Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
> > Cr-Commit-Position: refs/heads/master@{#20796}
> 
> TBR=magjed@webrtc.org,sakal@webrtc.org
> 
> Change-Id: I45f8d19abd81386872b7c095ac7eca21fa06077c
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: webrtc:8278,webrtc:8556
> Reviewed-on: https://webrtc-review.googlesource.com/24622
> Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
> Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20800}

TBR=magjed@webrtc.org,sakal@webrtc.org

Change-Id: I7cc404993addb17f0397127a10aac67476ef6ff4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:8278, webrtc:8556
Reviewed-on: https://webrtc-review.googlesource.com/24623
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20801}
diff --git a/sdk/android/BUILD.gn b/sdk/android/BUILD.gn
index ea5b4b4..9daae54 100644
--- a/sdk/android/BUILD.gn
+++ b/sdk/android/BUILD.gn
@@ -269,6 +269,15 @@
   }
 }
 
+generate_jni("generated_peerconnection_jni") {
+  sources = [
+    "api/org/webrtc/NetworkMonitor.java",
+    "api/org/webrtc/NetworkMonitorAutoDetect.java",
+  ]
+  jni_package = ""
+  jni_generator_include = "//sdk/android/src/jni/jni_generator_helper.h"
+}
+
 rtc_static_library("peerconnection_jni") {
   sources = [
     "src/jni/androidnetworkmonitor_jni.h",
@@ -328,6 +337,7 @@
 
   deps = [
     ":base_jni",
+    ":generated_peerconnection_jni",
     "../..:webrtc_common",
     "../../api/video_codecs:video_codecs_api",
     "../../media:rtc_data",