Add a missing Windows library

"oleaut32.lib" is required for VariantInit: https://docs.microsoft.com/en-us/windows/win32/api/oleauto/nf-oleauto-variantinit

Bug: webrtc:11807
Change-Id: If0511571340e14407ad9402636a4a64d328fabca
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/180440
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Eric Astor <epastor@google.com>
Cr-Commit-Position: refs/heads/master@{#31806}

modules/audio_device/BUILD.gn

@@ -112,6 +112,8 @@ rtc_source_set("windows_core_audio_utility") {
       "../../rtc_base:checks",
       "../../rtc_base:rtc_base_approved",
     ]
+
+    libs = [ "oleaut32.lib" ]
   }
 }
 
@@ -313,6 +315,7 @@ rtc_library("audio_device_impl") {
           "wmcodecdspuuid.lib",
           "amstrmid.lib",
           "msdmo.lib",
+          "oleaut32.lib",
         ]
       }
       configs += [ ":audio_device_warnings_config" ]

modules/video_capture/BUILD.gn

@@ -78,7 +78,10 @@ if (!build_with_chromium) {
         "windows/video_capture_factory_windows.cc",
       ]
 
-      libs = [ "strmiids.lib" ]
+      libs = [
+        "oleaut32.lib",
+        "strmiids.lib",
+      ]
 
       if (build_with_mozilla) {
         sources += [