Update SALT on SDK metrics to sync with other SDKs (#8268)

Realm/RLMAnalytics.mm

@@ -190,7 +190,7 @@ static auto RLMSysCtl(int *mib, u_int mibSize, size_t *bufferSize) {
     if ([ioPlatformUuid length] == 0) {
         return nil;
     }
-    NSString *salt = @"realm is great";
+    NSString *salt = @"Realm is great";
     NSString *saltedId = [ioPlatformUuid stringByAppendingString:salt];
     NSData *data = [saltedId dataUsingEncoding:NSUTF8StringEncoding];