Change allowed channels in ChromeLabs unittests

Since UNKNOWN is the least stable channel these features wouldn't work when run with official builds. Changing allowed channel to STABLE.

Bug: 1165704
Change-Id: I5822c9c719cda9336bc50e39eeadb8e0b3438c24
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2626915
Commit-Queue: Caroline Rising <corising@chromium.org>
Auto-Submit: Elaine Chien <elainechien@chromium.org>
Reviewed-by: Caroline Rising <corising@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843559}

chrome/browser/ui/views/toolbar/chrome_labs_bubble_view_unittest.cc

@@ -70,15 +70,15 @@ class ChromeLabsBubbleTest : public TestWithBrowserView {
   void CreateTestLabInfo() {
     test_feature_info_.emplace_back(
         LabInfo(kFirstTestFeatureId, base::ASCIIToUTF16(""),
-                base::ASCIIToUTF16(""), version_info::Channel::UNKNOWN));
+                base::ASCIIToUTF16(""), version_info::Channel::STABLE));
 
     test_feature_info_.emplace_back(
         LabInfo(kSecondTestFeatureId, base::ASCIIToUTF16(""),
-                base::ASCIIToUTF16(""), version_info::Channel::UNKNOWN));
+                base::ASCIIToUTF16(""), version_info::Channel::STABLE));
 
     test_feature_info_.emplace_back(
         LabInfo(kThirdTestFeatureId, base::ASCIIToUTF16(""),
-                base::ASCIIToUTF16(""), version_info::Channel::UNKNOWN));
+                base::ASCIIToUTF16(""), version_info::Channel::STABLE));
   }
 
   const std::vector<LabInfo>& GetTestLabInfo() { return test_feature_info_; }