Revert "Only register WidgetInspectorService extension in debug builds." (#22366)
Revert "Only register WidgetInspectorService extension in debug builds." (#22366)

This reverts commit 11350fed7f9d2088232354a131ca35a6e0aa6307.
tvolkert/flutter,Hixie/flutter,Hixie/flutter,cbracken/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,tvolkert/flutter,cbracken/flutter,tvolkert/flutter,Hixie/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,tvolkert/flutter,cbracken/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,flutter/flutter,cbracken/flutter