Add Null Guard

Issue gh-17933

Author: jzheaux

web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedAuthenticationProvider.java

@@ -157,6 +157,7 @@ public void setUserDetailsChecker(UserDetailsChecker userDetailsChecker) {
 	 * @param grantedAuthoritySupplier the supplier that grants authorities
 	 */
 	public void setGrantedAuthoritySupplier(Supplier<Collection<GrantedAuthority>> grantedAuthoritySupplier) {
+		Assert.notNull(grantedAuthoritySupplier, "grantedAuthoritySupplier cannot be null");
 		this.grantedAuthoritySupplier = grantedAuthoritySupplier;
 	}