Fix ClangTidy warnings

* converting integer literal to bool, use bool literal instead
* use '= default' to define a trivial default constructor

PiperOrigin-RevId: 554935854
Change-Id: If16a435664641df049b8810044b34a05ea2b4028

absl/strings/str_replace_test.cc

@@ -179,7 +179,7 @@ TEST(StrReplaceAll, ReplacementsInPlaceInMap) {
 }
 
 struct Cont {
-  Cont() {}
+  Cont() = default;
   explicit Cont(absl::string_view src) : data(src) {}
 
   absl::string_view data;