Build fixes for Winit based examples

The latest branches for Winit (which update the Android backend to
use android-activity) now depend on the android-activity 0.2
release which broke the patching assumption for the Winit examples.
(they were patching based on the git url not crates.io)

It was also noticed that the latest android-activity-0.27 branch
isn't compatible with Egui currently because the (badly named) branch
is based on Winit master and there was recently a breaking API change
adding new window events which breaks Egui.

A note about the badly name branches has been added to the Cargo.toml
files for the Winit examples (they can't currently be fixes since
the -0.27 branch is part of a pull request).

For reference here:
- "android-activity" is based on Winit 0.27 (required for Egui compatibility)
- "android-activity-0.27" is based on Winit master

This patch adds Cargo.lock files for the Winit examples.

Fixes: #22

Author: rib

agdk-eframe/.gitignore

@@ -19,4 +19,3 @@ local.properties
 # Added by cargo
 
 /target
-Cargo.lock