新增加载条动画，新增错误页面展示

app/src/main/java/chaoran/business/activity/AboutActivity.java

@@ -20,7 +20,8 @@ public class AboutActivity extends AppCompatActivity {
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_about);
-        setTitle(R.string.activity_about);
+        //隐藏状态栏
+        getSupportActionBar().hide();
         TextView textView = findViewById(R.id.about_content);
         textView.setText(R.string.activity_about_content);
     }