Misc logging changes

- log search result count, rank when clicking search result.
- log app package when default app is changed

Change-Id: Idd11bd67caba2beaa59c65839c40db8c71787388
Fix: 62072727
Test: make RunSettingsRoboTests

tests/robotests/src/com/android/settings/search/SavedQueryLoaderTest.java

@@ -59,7 +59,7 @@ public class SavedQueryLoaderTest {
 
     @After
     public void cleanUp() {
-        DatabaseTestUtils.clearDb();
+        DatabaseTestUtils.clearDb(mContext);
     }
 
     @Test