Fix: JNA issue in release mode (#335)

* Restore checkout config for nightly workflows.

* Add missing proguard config line for JNA.

app/proguard-rules.pro

@@ -6,6 +6,7 @@
 #   http://developer.android.com/guide/developing/tools/proguard.html
 
 # JNA
+-dontwarn java.awt.*
 -keep class com.sun.jna.** { *; }
 -keep class * implements com.sun.jna.** { *; }
 
@@ -23,4 +24,4 @@
 }
 -keepclassmembers class <1>.<2> {
   <1>.<2>$Companion Companion;
-}
+}