bytes,strings: use a more universal Cyrillic word

The word "брат" (brother) is the same across Slavic languages that
use the Cyrillic script, such as Bulgarian, Macedonian, Russian,
Ukrainian, and others.

Change-Id: I5155e6bb16a02dec5d93a01b79f9570f43f09444
Reviewed-on: https://go-review.googlesource.com/c/go/+/603535
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: David Chase <drchase@google.com>

src/bytes/example_test.go

@@ -502,10 +502,10 @@ func ExampleTitle() {
 
 func ExampleToTitle() {
 	fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises")))
-	fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб")))
+	fmt.Printf("%s\n", bytes.ToTitle([]byte("брат")))
 	// Output:
 	// LOUD NOISES
-	// ХЛЕБ
+	// БРАТ
 }
 
 func ExampleToTitleSpecial() {

src/strings/example_test.go

@@ -328,22 +328,22 @@ func ExampleTitle() {
 	// Compare this example to the ToTitle example.
 	fmt.Println(strings.Title("her royal highness"))
 	fmt.Println(strings.Title("loud noises"))
-	fmt.Println(strings.Title("хлеб"))
+	fmt.Println(strings.Title("брат"))
 	// Output:
 	// Her Royal Highness
 	// Loud Noises
-	// Хлеб
+	// Брат
 }
 
 func ExampleToTitle() {
 	// Compare this example to the Title example.
 	fmt.Println(strings.ToTitle("her royal highness"))
 	fmt.Println(strings.ToTitle("loud noises"))
-	fmt.Println(strings.ToTitle("хлеб"))
+	fmt.Println(strings.ToTitle("брат"))
 	// Output:
 	// HER ROYAL HIGHNESS
 	// LOUD NOISES
-	// ХЛЕБ
+	// БРАТ
 }
 
 func ExampleToTitleSpecial() {