Aperture: Implement QR scanner

Change-Id: Ie6011ed5e5782c8244777f3026e8a6f308820113
diff --git a/app/build.gradle b/app/build.gradle
index 3b5842f..e2d0ea7 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -55,4 +55,7 @@
     implementation "androidx.camera:camera-mlkit-vision:${camerax_version}"
     // If you want to additionally use the CameraX Extensions library
     implementation "androidx.camera:camera-extensions:${camerax_version}"
+
+    // ZXing
+    implementation 'com.google.zxing:core:3.5.0'
 }
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