Add build-id to libjingle_peerconnection_so.so

This is required by Firebase Crashlytics:
https://firebase.google.com/docs/crashlytics/ndk-reports#enable-symbol-uploading

Bug: None
Change-Id: Ie0d2c2e92477df78b26b7e1fc2273589b71efa81
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/210965
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33408}

sdk/android/BUILD.gn

@@ -141,7 +141,7 @@ if (is_android) {
 
     suppressed_configs += [ "//build/config/android:hide_all_but_jni_onload" ]
     configs += [ "//build/config/android:hide_all_but_jni" ]
-    ldflags = [ "-lEGL" ]
+    ldflags = [ "-lEGL", "-Wl,--build-id" ]
 
     deps = [
       ":libjingle_peerconnection_jni",