Add Amazon consumer proguard rules to plugin and prepare alpha.3 rele…

…ase (RevenueCat#336)

* adds proguard rules to plugin

* increase version

* add changelog and updates instructions

* removes unnecessary import

Prep for 3.9.5 release (RevenueCat#331)

Prep for 3.9.4 release (RevenueCat#326)

Prep for release 3.9.3 (RevenueCat#311)

Release 3.9.2 (RevenueCat#303)

* Release 3.9.2

* Updates changelog

Co-authored-by: Cesar de la Vega <cesarvegaro@gmail.com>

Release: 3.9.0 (RevenueCat#289)