Updated GIDTokenClaim Implementation + Tests with const string

Author: AkshatG6

GoogleSignIn/Sources/GIDTokenClaim.m

@@ -16,6 +16,8 @@
 
 #import "GoogleSignIn/Sources/Public/GoogleSignIn/GIDTokenClaim.h"
 
+NSString * const kAuthTimeClaimName = @"auth_time";
+
 // Private interface to declare the internal initializer
 @interface GIDTokenClaim ()
 
@@ -39,11 +41,11 @@ - (instancetype)initWithName:(NSString *)name essential:(BOOL)essential {
 #pragma mark - Factory Methods
 
 + (instancetype)authTimeClaim {
-  return [[self alloc] initWithName:@"auth_time" essential:NO];
+  return [[self alloc] initWithName:kAuthTimeClaimName essential:NO];
 }
 
 + (instancetype)essentialAuthTimeClaim {
-  return [[self alloc] initWithName:@"auth_time" essential:YES];
+  return [[self alloc] initWithName:kAuthTimeClaimName essential:YES];
 }
 
 #pragma mark - NSObject

GoogleSignIn/Sources/Public/GoogleSignIn/GIDTokenClaim.h

@@ -18,6 +18,8 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+extern NSString *const kAuthTimeClaimName;
+
 /**
  * An object representing a single OIDC claim to be requested for an ID token.
  */

GoogleSignIn/Tests/Unit/GIDTokenClaimTest.m

@@ -16,8 +16,6 @@
 #import <XCTest/XCTest.h>
 #import "GoogleSignIn/Sources/Public/GoogleSignIn/GIDTokenClaim.h"
 
-static NSString *const kAuthTimeClaimName = @"auth_time";
-
 @interface GIDTokenClaimTest : XCTestCase
 @end