Android: Fix settings activity back button stopping emulation

android/app/src/main/java/com/github/stenzek/duckstation/SettingsActivity.java

@@ -1,7 +1,9 @@
 package com.github.stenzek.duckstation;
 
 import android.os.Bundle;
+import android.view.MenuItem;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.preference.PreferenceFragmentCompat;
@@ -22,6 +24,16 @@ public class SettingsActivity extends AppCompatActivity {
         }
     }
 
+    @Override
+    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
+        if (item.getItemId() == android.R.id.home) {
+            onBackPressed();
+            return true;
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+
     public static class SettingsFragment extends PreferenceFragmentCompat {
         @Override
         public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {