Update Settings search result unique ids

- SearchResult stableIds are now DocIds from the database
- DocIds are data reference key's hash, when the key is not
empty or null
- Otherwise, DocIds are a hashcode from a set of fields.

Change-Id: Id36f7bf4ceaaa3a2bd326ecafbfe97fd0b247df2
Fixes: 37327194
Test: make RunSettingsRoboTest

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

@@ -95,10 +95,11 @@ public class InstalledAppResultLoader extends AsyncLoader<List<? extends SearchR
 
                 final AppSearchResult.Builder builder = new AppSearchResult.Builder();
                 builder.setAppInfo(info)
-                        .addTitle(info.loadLabel(pm))
-                        .addRank(getRank(wordDiff))
+                        .setStableId(info.packageName.hashCode())
+                        .setTitle(info.loadLabel(pm))
+                        .setRank(getRank(wordDiff))
                         .addBreadcrumbs(getBreadCrumb())
-                        .addPayload(new ResultPayload(intent));
+                        .setPayload(new ResultPayload(intent));
                 results.add(builder.build());
             }
         }