Made strings in the uimanager resource folder non translatable

Summary:
In D8884991, I added a strings.xml file to react-native-github UI Manager resources.
Because this gets deployed to open source, and not all apps have the same Locale support that Facebook has, we temporarily don't want these strings to be translated.

I added `translatable = false` to the strings in this diff.

Reviewed By: fkgozali

Differential Revision: D9018766

fbshipit-source-id: 04d06478d0ac665fa02387e6df035c31522fdea6

Author: Ziqi Chen