What is the non SDK Ljava/lang/invoke/MethodHandles$Lookup;->(Ljava/lang/Class;I)V API?

Question

Unity

the game is fully working, uploaded to the playlist and downloaded, it works stably, but in all versions there is a warning

API not from SDK Ljava/lang/invoke/MethodHandles$Lookup;->(Ljava/lang/Class;I)V

What is it, how to get rid of it?
I looked in the net, they wrote that because of this there could be failures, I really didn’t find a solution to this issue, I decided to ask people here what it is and how to get rid of it ....