android_jni: Add proguard rules for native code

Without this change, proguard will obfuscate members of the Info
class, which is being accessed by the native methods. The native
JNI code will crash as it will not be able to find the members with
their original names.

Fixes bumptech/glide#4761.

android_jni/avifandroidjni/proguard-rules.pro

@@ -1,21 +1,14 @@
-# Add project specific ProGuard rules here.
-# You can control the set of applied configuration files using the
-# proguardFiles setting in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
+# Proguard rules for the JNI Bindings.
+# For explanation, see:
+# https://www.guardsquare.com/manual/configuration/examples#native
 
-# If your project uses WebView with JS, uncomment the following
-# and specify the fully qualified class name to the JavaScript interface
-# class:
-#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
-#   public *;
-#}
+# Keep the names of the native methods unobfuscated.
+-keepclasseswithmembernames,includedescriptorclasses class * {
+  native <methods>;
+}
 
-# Uncomment this to preserve the line number information for
-# debugging stack traces.
-#-keepattributes SourceFile,LineNumberTable
-
-# If you keep the line number information, uncomment this to
-# hide the original source file name.
-#-renamesourcefileattribute SourceFile
+# Members of this class may be accessed from native methods. Keep them
+# unobfuscated.
+-keep class org.aomedia.avif.android.AvifDecoder$Info {
+  *;
+}