[java-inspections] LambdaCanBeMethodReference: avoid conversion to cast on invalid type

Fixes EA-429448 - AE: LambdaCanBeMethodReferenceInspection.lambda$getLambdaToMethodReferenceConversionCandidate$0

GitOrigin-RevId: 51471968b691b383659da01bad4360493a04e46e

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/lambda2methodReference/beforeCastInvalidType.java

@@ -0,0 +1,8 @@
+// "Replace lambda with method reference" "false"
+import java.util.function.Function;
+
+class Bar extends Random {
+  public void test(Object obj) {
+    Function<Object, String> fn = s -> (String.)<caret>s;
+  }
+}