Fix build failure with newer toolchains.

Android somehow wants every string to be externalized on newer
toolchains, let's prepare for that.

This fixes in-tree building of f-droid.

res/layout/repodiscoveryitem.xml

@@ -10,7 +10,7 @@
           android:maxLines="1"
           android:paddingLeft="8sp"
           android:paddingStart="8sp"
-          android:text="Discovered Repo Name"
+          android:text="@string/discovered_repo_name"
           android:textSize="16sp"
           android:textStyle="bold" />
 
@@ -23,7 +23,7 @@
           android:paddingLeft="8sp"
           android:paddingStart="8sp"
           android:maxLines="1"
-          android:text="Repo Address"
+          android:text="@string/repo_address"
           android:textSize="14sp" />
 
 </RelativeLayout>

res/values/strings.xml

@@ -210,4 +210,7 @@
     <string name="not_on_same_wifi">Your device is not on the same WiFi as the local repo you just added! Try joining this network: %s</string>
     <string name="requires_features">Requires: %1$s</string>
 
+    <string name="discovered_repo_name">Discovered Repo Name</string>
+    <string name="repo_address">Repo Address</string>
+
 </resources>