fix: don't rename R class fields alias (PR #492)

* fix: R class fields alias
* implemented with clearer approach

jadx-core/src/main/java/jadx/core/deobf/Deobfuscator.java

@@ -11,6 +11,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
 
+import jadx.core.dex.attributes.AFlag;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
@@ -225,6 +226,8 @@ public class Deobfuscator {
 			clsInfo.rename(cls.dex().root(), fullName);
 		}
 		for (FieldNode field : cls.getFields()) {
+			if (field.contains(AFlag.DONT_RENAME))
+			    continue;
 			renameField(field);
 		}
 		for (MethodNode mth : cls.getMethods()) {

jadx-core/src/main/java/jadx/core/dex/attributes/AFlag.java

@@ -19,6 +19,7 @@ public enum AFlag {
 	DONT_SHRINK,
 	DONT_INLINE,
 	DONT_GENERATE,
+	DONT_RENAME, // do not rename during deobfuscation
 	SKIP,
 	REMOVE,
 

jadx-core/src/main/java/jadx/core/utils/android/AndroidResourcesUtils.java

@@ -6,6 +6,7 @@ import java.util.Map;
 import java.util.TreeMap;
 
 import com.android.dx.rop.code.AccessFlags;
+import jadx.core.dex.attributes.AFlag;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
@@ -124,6 +125,7 @@ public class AndroidResourcesUtils {
 			if (fieldNode != null
 					&& !fieldNode.getName().equals(resName)
 					&& NameMapper.isValidIdentifier(resName)) {
+				fieldNode.add(AFlag.DONT_RENAME);
 				fieldNode.getFieldInfo().setAlias(resName);
 			}
 		}