Earlier my gradle was like this: WHICH IS OFCOURSE INCORRECT
apply plugin: \'android\'
android {
compileSdkVersion 19
buildToo
The comment by pyus13 is what i would go by.
It says in the documentation (http://developer.android.com/tools/publishing/app-signing.html) that:
"Note: Including the passwords for your release key and keystore inside the build file is not a good security practice. Alternatively...have the build process prompt you for these passwords."
So just do Build > Generate signed apk and Android studio will prompt you for the keystore/passwords and generate the apk in release mode. No need to put passwords in build file.
On the lower left of the Studio window there's a docked view called "Build Variants".
Open it and choose the release variant.
ps. you are adding compile 'com.google.android.gms:play-services:+' twice.