Fix hardware keyboard in Android emulator

Since Android SDK r20 hardware keyboard in emulator stopped working by default. To get it back, just add the following string:

hw.keyboard=yes

To your AVDs' config.ini files located in $HOME/.android/avd/*.avd/config.ini:

Here's the quick shell command for the rescue:

for f in "$HOME/.android/avd/*.avd/config.ini"; do echo 'hw.keyboard=yes' >> "$f"; done