Use a literal string for versionName in AM.xml

It's handier to have just the one resource version_name, but lint gets very
angry at this (and there must be a reason for that). We must not forget to
update the resource in res/values/no_trans.xml, since it's still used in the
code.

AndroidManifest.xml

@@ -3,7 +3,7 @@
     package="org.fdroid.fdroid"
     android:installLocation="auto"
     android:versionCode="560"
-    android:versionName="@string/version_name" >
+    android:versionName="0.56-test" >
 
     <uses-sdk
         android:minSdkVersion="5"