Use .fullyExpandedType to get serializable annotation from inside typealias

to correctly handle 'global customization via typealias' feature
in K2 serialization plugin.

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirBlackBoxTestGenerated.java

@@ -128,6 +128,12 @@ public class SerializationFirBlackBoxTestGenerated extends AbstractSerialization
         public void testStarProjections() throws Exception {
             runTest("plugins/kotlinx-serialization/testData/boxIr/starProjections.kt");
         }
+
+        @Test
+        @TestMetadata("typealiasesTest.kt")
+        public void testTypealiasesTest() throws Exception {
+            runTest("plugins/kotlinx-serialization/testData/boxIr/typealiasesTest.kt");
+        }
     }
 
     @Nested

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationIrBoxTestGenerated.java

@@ -126,4 +126,10 @@ public class SerializationIrBoxTestGenerated extends AbstractSerializationIrBoxT
     public void testStarProjections() throws Exception {
         runTest("plugins/kotlinx-serialization/testData/boxIr/starProjections.kt");
     }
+
+    @Test
+    @TestMetadata("typealiasesTest.kt")
+    public void testTypealiasesTest() throws Exception {
+        runTest("plugins/kotlinx-serialization/testData/boxIr/typealiasesTest.kt");
+    }
 }