Delete DynamicindexableContentMonitor & all refs to it

Convert input device search into a search query loader

And remove old logic from DynamicIndexableContentMonitor

Change-Id: If652b1ea7c8add9185bbd025055e14925d3a8eec
Bug: 64310452
Bug: 63831980
Test: robotests

src/com/android/settings/search/SearchFeatureProvider.java

@@ -48,6 +48,11 @@ public interface SearchFeatureProvider {
     AccessibilityServiceResultLoader getAccessibilityServiceResultLoader(Context context,
             String query);
 
+    /**
+     * Returns a new loader to search input devices.
+     */
+    InputDeviceResultLoader getInputDeviceResultLoader(Context context, String query);
+
     /**
      * Returns a new loader to get all recently saved queries search terms.
      */