This consolidates all of the non-template .gitignore rules into the top level .gitignore, to ignore common things more broadly, with less maintenance needed for the .gitignore files. Does not touch the templates, so that they still produce needed .gitignores as part of flutter create.
* Remove stray PRODUCT_BUNDLE_IDENTIFIER
This was erroneously added and overrides
the bundle for the gallery causing signing
to fail in my setup.
@chinmaygarde
* Remove PRODUCT_BUNDLE_IDENTIFIER from all Runner pbxproj's
We now use a different approach for ios projects where the developer controls
the Xcode project file. This patch removes the old ".generated" approach in
favor of the new approach.
