[FIR] Fix generic sam conversion in call completion

#KT-60903 Fixed

jps/jps-plugin/testData/incremental/pureKotlin/samConversion/main.kt

@@ -0,0 +1,17 @@
+fun main() {
+    Observable.of(1, 2)
+        .apply({ observable ->
+            Observable { subscriber ->
+                (observable).subscribe(object : Observer<Int> {
+                    override fun next(value: Int) {
+                        subscriber.next(value * 2)
+                    }
+
+                })
+            }
+        })
+        .subscribe(object : Subscriber<Int>() {
+            override fun next(value: Int) {
+            }
+        })
+}