Improve the labels of the flavors, update the README (#379)

README.md

@@ -83,6 +83,14 @@ ISO/IEC 18013-5:2021 and the other three have been used at mdoc/mDL
 test events organized by participants of the ISO/IEC JTC1 SC17 WG10
 working group.
 
+The `appholder` offers two flavors: `wallet` and `purse`. There is not much difference between
+the two, except they have different application id, so they can coexist in a single device.
+They also have different labels and icon color. To select the desired flavor when running the app
+on a device/emulator, inside the Android Studio open the `Build Variants` panel. It should be easily 
+reachable on the left side bar of the Android Studio, or by selecting: _View -> Tool Windows -> Build Variants_.
+Inside the `Build Variants` panel, at the `appholder` row, the desired flavor can be chosen. Once a
+flavor is selected, by running the app it will install it on the target device/emulator.
+
 ## ISO 18013-7 Reader Website
 
 The `wwwverifier` module contains the source code for a website acting as an

appholder/src/main/res/navigation/navigation_graph.xml

@@ -23,7 +23,7 @@
     <fragment
         android:id="@+id/wallet"
         android:name="com.android.identity.wallet.wallet.SelectDocumentFragment"
-        android:label="@string/menu_wallet"
+        android:label="@string/app_name"
         tools:layout="@layout/fragment_select_document">
         <action
             android:id="@+id/toDocumentDetail"

appholder/src/main/res/values/strings.xml

@@ -7,7 +7,7 @@
     <string name="txt_transferring">Transferring</string>
     <string name="txt_consent">Approve sending data to mDL verifier</string>
     <string name="bt_approve">Approve</string>
-    <string name="nfc_engagement_service_desc">mDL NFC Engagement</string>
+    <string name="nfc_engagement_service_desc">@string/app_name</string>
     <string name="nfc_data_transfer_service_desc">mDL NFC Data Transfer</string>
     <string name="engagement_aid_group_desc">mDL AID Group</string>
     <string name="bt_add_document">Add Document</string>