Stop preguarding

[ashwinraghav]

Firebase SDKs are currently shipped as proguarded artifacts.

Among other things, we have been doing this to minimize the size impact for the millions of developers who chose to not proguard their own apps. While this continues to have the desired effect for libraries that bake in dependencies, all open sourced projects have dependencies that are brought in via pom files that accompany releases.

Firebase Storage

App Proguard Enabled	SDK Proguard Enabled	apk size
Yes	Yes	739K
Yes	No	740K
No	Yes	1.6M
No	No	1.7M

Firebase Functions

App Proguard Enabled	SDK Proguard Enabled	apk size
Yes	Yes	804K
Yes	No	804K
No	Yes	1.8M
No	No	1.8M

Firebase Firestore

App Proguard Enabled	SDK Proguard Enabled	apk size
Yes	Yes	1.3M
Yes	No	1.3M
No	Yes	3.9M
No	No	4.0M

Firebase Database

App Proguard Enabled	SDK Proguard Enabled	apk size
Yes	Yes	769K
Yes	No	830K
No	Yes	1.8M
No	No	1.8M

With dependencies being brought in by the developer's build system based on the pom.xml, it can be seen that any significant improvement in size can come only if the developer proguards their apk.

Given the limited value that proguarding the SDK itself has, it makes sense to stop proguarding SDKs in the interest of easier debugging and simpler tooling

[DevByStarlight]

Thanks for the analysis @ashwinraghav.

However, @bjornick or whoever, I am curious what proguard exception rules were used so we can use the same rules in our application builds.

If the answer is: "depends on which library", then is the best approach to dig, individually, though the sub-projects in the Firebase Quickstart Android GitHub?