This change avoids all need for changing any file under
VCS to insert signing keys and configs for release builds.
Example contents of keystore.properties
```
// Location of keystore, relative to module build.gradle,
// in this case, of the app module
storeFile=../wireguard.jks
storePassword=b3ty0uc4nth4xxth1s
keyAlias=wireguard
keyPassword=4ndr01dsux
```
Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>