Add dialog giving the user scan/manually enter options (#111)

app/src/main/java/protect/card_locker/BarcodeValues.java

@@ -0,0 +1,23 @@
+package protect.card_locker;
+
+public class BarcodeValues {
+    private final String mFormat;
+    private final String mContent;
+
+    public BarcodeValues(String format, String content) {
+        mFormat = format;
+        mContent = content;
+    }
+
+    public String format() {
+        return mFormat;
+    }
+
+    public String content() {
+        return mContent;
+    }
+
+    public boolean isEmpty() {
+        return mFormat == null && mContent == null;
+    }
+}