Add missing Remote Config classes to proguard (#1350)

* Add missing Remote Config classes to proguard

* Update readme.md

Author: a-maurice

release_build_files/readme.md

@@ -630,6 +630,8 @@ code.
 ### Upcoming Release
 -   Changes
     - App Check (Desktop): Fixed expired tokens being cached on 32-bit systems.
+    - Remote Config (Android): Fixed the ConfigUpdate classes being missing
+      from the proguard files.
     - Remote Config (Desktop): Fixed handling of time zones on Windows when the
       time zone name in the current system language contains an accented
       character or apostrophe. This adds a requirement for applications using

remote_config/src/android/remote_config_android.cc

@@ -171,6 +171,7 @@ METHOD_LOOKUP_DECLARATION(jni_config_update_listener,
                           JNI_CONFIG_UPDATE_LISTENER_METHODS)
 METHOD_LOOKUP_DEFINITION(
     jni_config_update_listener,
+    PROGUARD_KEEP_CLASS
     "com/google/firebase/remoteconfig/internal/cpp/JniConfigUpdateListener",
     JNI_CONFIG_UPDATE_LISTENER_METHODS)
 
@@ -195,6 +196,7 @@ static const JNINativeMethod kNativeJniConfigUpdateListenerMethods[] = {
 
 METHOD_LOOKUP_DECLARATION(config_update, CONFIG_UPDATE_METHODS)
 METHOD_LOOKUP_DEFINITION(config_update,
+                         PROGUARD_KEEP_CLASS
                          "com/google/firebase/remoteconfig/ConfigUpdate",
                          CONFIG_UPDATE_METHODS)
 
@@ -208,6 +210,7 @@ METHOD_LOOKUP_DECLARATION(config_update_listener_registration,
                           CONFIG_UPDATE_LISTENER_REGISTRATION_METHODS)
 METHOD_LOOKUP_DEFINITION(
     config_update_listener_registration,
+    PROGUARD_KEEP_CLASS
     "com/google/firebase/remoteconfig/ConfigUpdateListenerRegistration",
     CONFIG_UPDATE_LISTENER_REGISTRATION_METHODS)