jextract: Suppress InternalImportsByDefault related warnings (#719)

Author: sidepelican

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+SwiftThunkPrinting.swift

@@ -842,10 +842,15 @@ extension JNISwift2JavaGenerator {
       """
       // Generated by swift-java
 
+      #if hasFeature(InternalImportsByDefault)
       public import SwiftJava
       public import SwiftJavaJNICore
       public import SwiftJavaRuntimeSupport
-
+      #else
+      import SwiftJava
+      import SwiftJavaJNICore
+      import SwiftJavaRuntimeSupport
+      #endif
       """
     )