Remove assert about release mode (#64813)
Remove assert about release mode (#64813)

b/150295238 has been resolved for a while now.
cbracken/flutter,cbracken/flutter,Hixie/flutter,cbracken/flutter,Hixie/flutter,tvolkert/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter