Memory Leak Issue, Tested in Android 11

[yusriltakeuchi]

Hi @kmcgill88, i use your package to show banner ads in my applications. When i check in the devtools, memory usage capacity becomes bigger when admob banner is displayed. Tested in profile mode.

I think when the page is closed, these banner Ads don't really disappear from memory, they are still there, so there is a memory leak