FIR: rename AMBIGUITY to OVERLOAD_RESOLUTION_AMBIGUITY to match FE 1.0

compiler/testData/diagnostics/tests/inference/cannotCompleteResolveNoInfoForParameter.fir.kt

@@ -5,7 +5,7 @@ fun <T> f(i: Int, c: Collection<T>): List<T> {throw Exception()}
 fun <T> f(a: Any, l: List<T>): Collection<T> {throw Exception()}
 
 fun <T> test(l: List<T>) {
-    <!AMBIGUITY!>f<!>(1, emptyList())
+    <!OVERLOAD_RESOLUTION_AMBIGUITY!>f<!>(1, emptyList())
 }
 
 fun <T> emptyList(): List<T> {throw Exception()}