Do not use string resources for app label

This not only simplifies hiding stub APKs (no resource IDs involved),
but also opens the opportunity to allow users to customize whatever
app name they want after it is hidden.

app/proguard-rules.pro

@@ -32,7 +32,7 @@
 -keep,allowobfuscation class * extends com.topjohnwu.magisk.base.DelegateWorker
 
 # BootSigner
--keepclassmembers class com.topjohnwu.signing.BootSigner { *; }
+-keep class a.a { *; }
 
 # Strip logging
 -assumenosideeffects class timber.log.Timber.Tree { *; }