Added proguard rules to the AAR-package

usbserial/build.gradle

@@ -19,6 +19,7 @@ android {
         minSdkVersion Integer.parseInt(project.ANDROID_BUILD_MIN_SDK_VERSION)
         targetSdkVersion Integer.parseInt(project.ANDROID_BUILD_TARGET_SDK_VERSION)
         archivesBaseName = "${project.name}-${project.VERSION_NAME}"
+        consumerProguardFiles 'proguard-rules.pro'
     }
 
     //noinspection GroovyAssignabilityCheck

usbserial/proguard-rules.pro

@@ -15,3 +15,6 @@
 #-keepclassmembers class fqcn.of.javascript.interface.for.webview {
 #   public *;
 #}
+
+# Animal Sniffer compileOnly dependency to ensure APIs are compatible with older versions of Java.
+-dontwarn org.codehaus.mojo.animal_sniffer.*