As of Xcode 7, Apple recommends setting the bundle identifier in the
PRODUCT_BUNDLE_IDENTIFIER build variable and setting CFBundleIdentifier
to that variable in Info.plist.

As of Xcode 8, CLANG_WARN_INFINITE_RECURSION and CLANG_WARN_SUSPICIOUS_MOVE
are recommended settings.

We want to use the FlutterViewController in this new project template.

Fixes #4840

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.