Bug 1285386 - Guard against NPE and other exceptions in SearchEngine creation; r=sebastian

mobile/android/base/java/org/mozilla/gecko/search/SearchEngineManager.java

@@ -661,7 +661,7 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
             } finally {
                 in.close();
             }
-        } catch (IOException | XmlPullParserException e) {
+        } catch (Exception e) {
             Log.e(LOG_TAG, "Exception creating search engine", e);
         }