Fix QR code scanner layout in "Pair devices over Wi-Fi" page.

The toolbar needs to be disabled to remove the empty space at the top
of the page. Also added the landscape layout xml.

Bug: 193602141
Test: atest SettingsUnitTests and manual

Change-Id: I30368835979b360a8f09e16f70adf57064784517
(cherry picked from commit fd009229e5)

src/com/android/settings/development/AdbQrCodeActivity.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.development;
+
+import android.app.settings.SettingsEnums;
+import android.content.Intent;
+import android.os.Bundle;
+
+import androidx.fragment.app.FragmentTransaction;
+
+import com.android.settings.R;
+import com.android.settings.wifi.dpp.WifiDppBaseActivity;
+
+/**
+ * To scan an ADB QR code to pair a device.
+ *
+ * To use intent action {@code ACTION_ADB_QR_CODE_SCANNER}.
+ */
+public class AdbQrCodeActivity extends WifiDppBaseActivity {
+    private static final String TAG = "AdbQrCodeActivity";
+
+    static final String TAG_FRAGMENT_ADB_QR_CODE_SCANNER = "adb_qr_code_scanner_fragment";
+
+    public static final String ACTION_ADB_QR_CODE_SCANNER =
+            "android.settings.ADB_QR_CODE_SCANNER";
+
+    @Override
+    public int getMetricsCategory() {
+        return SettingsEnums.SETTINGS_ADB_WIRELESS;
+    }
+
+    @Override
+    protected void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+        AdbQrcodeScannerFragment fragment =
+                (AdbQrcodeScannerFragment) mFragmentManager.findFragmentByTag(
+                        TAG_FRAGMENT_ADB_QR_CODE_SCANNER);
+
+        if (fragment == null) {
+            fragment = new AdbQrcodeScannerFragment();
+        } else {
+            if (fragment.isVisible()) {
+                return;
+            }
+
+            // When the fragment in back stack but not on top of the stack, we can simply pop
+            // stack because current fragment transactions are arranged in an order
+            mFragmentManager.popBackStackImmediate();
+            return;
+        }
+        final FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
+
+        fragmentTransaction.replace(R.id.fragment_container, fragment,
+                TAG_FRAGMENT_ADB_QR_CODE_SCANNER);
+        fragmentTransaction.commit();
+    }
+
+    @Override
+    protected void handleIntent(Intent intent) {
+    }
+}