Call `Library.load()` before calling native getCurrentSystemTheme function. (#866)

skiko/src/awtMain/kotlin/org/jetbrains/skiko/SystemTheme.awt.kt

 package org.jetbrains.skiko
 
 actual val currentSystemTheme: SystemTheme
-    get() = when (getCurrentSystemTheme()) {
+    get() {
+        Library.load()
+        return when (getCurrentSystemTheme()) {
             0 -> SystemTheme.LIGHT
             1 -> SystemTheme.DARK
             else -> SystemTheme.UNKNOWN
         }
+    }
 
 // Common
 private external fun getCurrentSystemTheme(): Int

skiko/src/awtTest/kotlin/org/jetbrains/skiko/LibraryLoadedTest.kt

+package org.jetbrains.skiko
+
+import org.junit.Test
+
+/**
+ * Verifies that the native Skiko library is correctly loaded in various scenarios.
+ */
+class LibraryLoadedTest {
+    @Test
+    fun getSystemTheme() {
+        currentSystemTheme
+    }
+}
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