Since you have not mentioned the proxy tool that you are using, I am going to assume it is Burp.
As a first step, export the certificate of Burp. To do this use the guide on below link and after "View Certificate step export the certificate onto your system. Verify that the file is saved with the extension ".crt"
http://portswigger.net/burp/help/proxy_options_installingCAcert.html
Now, copy this file into the sdcard of the emulator. You can use adb push to achieve this.
In the emulator navigate to Settings -> Security -> Credential storage: Install certificates from SD card
It will prompt you to enter a PIN code, enter the secret code and the certificate will be added. Now, access any HTTPS site you should be able to intercept in your proxy.