Refactor: Fix warnings

Author: zhanghai

app/src/main/java/me/zhanghai/android/textselectionwebsearch/EditTextPreferenceCompat.java

@@ -11,6 +11,7 @@
 import androidx.annotation.Nullable;
 import androidx.annotation.StyleRes;
 
+@SuppressWarnings("deprecation")
 public class EditTextPreferenceCompat extends EditTextPreference {
 
     private boolean mTextSetCompat;

app/src/main/java/me/zhanghai/android/textselectionwebsearch/SettingsActivity.java

@@ -21,7 +21,6 @@
 public class SettingsActivity extends PreferenceActivity
         implements SharedPreferences.OnSharedPreferenceChangeListener {
 
-    @NonNull
     private Preference mCustomSearchEngineUrlFormatPreference;
 
     @Override
@@ -43,7 +42,7 @@ protected void onCreate(@Nullable Bundle savedInstanceState) {
 
     @Override
     public void onSharedPreferenceChanged(@NonNull SharedPreferences sharedPreferences,
-                                          @NonNull String key) {
+                                          @Nullable String key) {
         if (Objects.equals(key, getString(R.string.pref_key_search_engine))) {
             updateCustomSearchEngineUrlFormatPreferenceVisibility();
         }

app/src/main/java/me/zhanghai/android/textselectionwebsearch/WebSearchActivity.java

@@ -141,6 +141,7 @@ private SharedPreferences getSharedPreferences() {
     }
 
     @NonNull
+    @SuppressWarnings("deprecation")
     private static SharedPreferences getSharedPreferences(@NonNull Context context) {
         return PreferenceManager.getDefaultSharedPreferences(context);
     }