Bluetooth Scanning API: Remove unnecessary blank option in site settings on Android

This CL removes unnecessary blank option in site settings on Android
when Bluetooth Scanning API is not enabled.

Bug: 980075
Change-Id: I70c39634e161cbcc28b805b12d7facfdcf2d5fb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1693766Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Commit-Queue: Jun Cai <juncai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676088}

chrome/android/java/src/org/chromium/chrome/browser/preferences/website/SiteSettingsPreferences.java

@@ -98,6 +98,10 @@ public class SiteSettingsPreferences
             if (FeatureUtilities.isNoTouchModeEnabled()) {
                 getPreferenceScreen().removePreference(findPreference(Type.CLIPBOARD));
             }
+            CommandLine commandLine = CommandLine.getInstance();
+            if (!commandLine.hasSwitch(ContentSwitches.ENABLE_WEB_BLUETOOTH_SCANNING)) {
+                getPreferenceScreen().removePreference(findPreference(Type.BLUETOOTH_SCANNING));
+            }
         }
     }