feat: add customizable label to GoogleSignInButton component

- Introduced a new 'label' prop to the GoogleSignInButton, allowing users to customize the button text.
- Default label set to 'Sign in with Google' for improved user experience.

Author: IronTony

packages/google-signin/src/native/GoogleSignInButton.tsx

@@ -9,6 +9,7 @@ type GoogleSignInButtonProps = {
   onError?: (error: Error) => void;
   style?: StyleProp<ViewStyle>;
   disabled?: boolean;
+  label?: string;
 };
 
 export function GoogleSignInButton({
@@ -17,6 +18,7 @@ export function GoogleSignInButton({
   onError,
   style,
   disabled = false,
+  label = 'Sign in with Google',
 }: GoogleSignInButtonProps) {
   const [isLoading, setIsLoading] = useState(false);
 
@@ -74,7 +76,7 @@ export function GoogleSignInButton({
               color: '#3c4043',
             }}
           >
-            Sign in with Google
+            {label}
           </Text>
         </View>
       )}