アクティビティの挙動を修正

app/src/main/AndroidManifest.xml

@@ -9,6 +9,7 @@
         android:theme="@style/Theme.LIME">
         <activity
             android:name=".SettingsActivity"
+            android:clearTaskOnLaunch="true"
             android:exported="true" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/io/github/chipppppppppp/lime/SettingsActivity.java

@@ -78,7 +78,7 @@ public class SettingsActivity extends AppCompatActivity {
                 .setPositiveButton(context.getString(R.string.dialog_positive), new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
-                        finish();
+                        finishAndRemoveTask();
                     }
                 })
                 .setCancelable(false)