Proguard not supported by default

When using proguard + msal, the following rules are required to make the client work:

# This enum is accessed via reflection in common msal lib thus proguard removes it.
-keep public enum com.microsoft.identity.common.internal.ui.AuthorizationAgent  {
    *;
}

# Classes for below package is used by MSAL library. Ignore warning coming from the dependency.
-dontwarn com.nimbusds.jose.**

This rules can be packaged directly in the msal library and common library instead of asking developers to do so.

[guperrot]

This is what came up when fixing the rules when used in AppCenter:

https://github.com/microsoft/AppCenter-SDK-Android/pull/1149/files#diff-54abb45c98c994c8e22a56dc46f07a0b

This covers basic AAD B2C scenarios but you might want to apply that keep rules to every model or enum used via Gson.

[guperrot]

We can already do it in proguard, the Microsoft AppCenter SDK uses this already.

Just needs

android {

        defaultConfig {
            consumerProguardFiles 'proguard-rules.pro'

In the build.gradle for the library.

It will be automatically added by android gradle plugin as proguard.txt in the AAR file and added to app rules if consumed as a dependency.