Allow backup & restore to cloud and device transfer (#32)

app/src/main/AndroidManifest.xml

@@ -13,7 +13,7 @@
 
     <application
         android:name=".AuthenticatorApplication"
-        android:allowBackup="false"
+        android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"

app/src/main/res/xml/backup_rules.xml

@@ -1,18 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
-<full-backup-content>
-    <exclude
+<full-backup-content xmlns:tools="http://schemas.android.com/tools">
+    <include
         domain="sharedpref"
-        path="." />
-    <exclude
-        domain="file"
-        path="." />
+        path="com.x8bit.bitwarden.authenticator_preferences.xml" />
     <exclude
         domain="database"
-        path="." />
-    <exclude
-        domain="external"
-        path="." />
-    <exclude
-        domain="root"
-        path="." />
-</full-backup-content>
+        path="."
+        tools:ignore="FullBackupContent" />
+</full-backup-content>

app/src/main/res/xml/data_extraction_rules.xml

@@ -1,19 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?><!--
-   Sample data extraction rules file; uncomment and customize as necessary.
-   See https://developer.android.com/about/versions/12/backup-restore#xml-changes
-   for details.
--->
+<?xml version="1.0" encoding="utf-8"?>
 <data-extraction-rules>
     <cloud-backup>
-        <!-- TODO: Use <include> and <exclude> to control what is backed up.
-        <include .../>
-        <exclude .../>
-        -->
+        <include
+            domain="sharedpref"
+            path="com.x8bit.bitwarden.authenticator_preferences.xml" />
+        <include
+            domain="database"
+            path="." />
     </cloud-backup>
-    <!--
     <device-transfer>
-        <include .../>
-        <exclude .../>
+        <include
+            domain="sharedpref"
+            path="com.x8bit.bitwarden.authenticator_preferences.xml" />
+        <include
+            domain="database"
+            path="." />
     </device-transfer>
-    -->
-</data-extraction-rules>
+</data-extraction-rules>