Support highlighting the menu entry for Search results

1. Add a receiver to monitor the search state
2. Shoe/hide the menu highlight in the listener
3. Highlight the menu entry in SearchResultTrampoline
4. Enable/disable the receiver in SettingsInitialize

Bug: 205781792
Test: manual, robotest
Change-Id: Ia04901f504172f4f0c7b4b2ea7eda5f3713f676d
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 638340e..1cb9819 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -297,6 +297,15 @@
             </intent-filter>
         </activity>
 
+        <receiver android:name=".search.SearchStateReceiver"
+                  android:exported="true"
+                  android:permission="android.permission.READ_SEARCH_INDEXABLES">
+            <intent-filter>
+                <action android:name="com.android.settings.SEARCH_START"/>
+                <action android:name="com.android.settings.SEARCH_EXIT"/>
+            </intent-filter>
+        </receiver>
+
         <activity
             android:name="Settings$WifiSettingsActivity"
             android:label="@string/wifi_settings"