fix: Fix ExtensionsManager abstract method crash by adding ProGuard rule (#466)

android/build.gradle

@@ -88,6 +88,7 @@ android {
   defaultConfig {
     minSdkVersion 21
     targetSdkVersion getExtOrIntegerDefault('targetSdkVersion')
+    consumerProguardFiles 'proguard-rules.pro'
 
     externalNativeBuild {
       cmake {

android/proguard-rules.pro

@@ -0,0 +1,2 @@
+# VisionCamera (CameraX)
+-keep class androidx.camera.extensions.** { *; }