system activity for scan always available setting

Takes user permission via a dialog to enable scans to be always available.

Bug: 8141918
Change-Id: I1e5e45e514726c2cbfd86e747123e477e00fd7ed
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 4668dd9..abbd703 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -1179,6 +1179,15 @@
             </intent-filter>
         </activity>
 
+        <activity android:name=".wifi.WifiScanModeActivity"
+                  android:excludeFromRecents="true"
+                  android:theme="@style/Transparent">
+            <intent-filter>
+                <action android:name="android.net.wifi.action.REQUEST_SCAN_ALWAYS_AVAILABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+
         <activity android:name=".bluetooth.RequestPermissionHelperActivity"
                   android:label="@string/bluetooth_pairing_request"
                   android:excludeFromRecents="true"