Proposal to fix Android warnings.

(cherry picked from commit eb65bd4a17d7c750cc2eb1a44cbbc309a7ada068)

forge-gui-android/proguard.cfg

@@ -6,6 +6,7 @@
 -verbose
 -optimizations !code/simplification/arithmetic,!field/*,!class/merging/*,!code/allocation/variable
 
+-dontwarn afu.org.checkerframework.**
 -dontwarn io.netty.**
 -dontwarn org.eclipse.jetty.**
 -dontwarn com.thoughtworks.xstream.**
@@ -13,6 +14,7 @@
 -dontwarn org.apache.commons.**
 -dontwarn com.google.guava.**
 -dontwarn com.google.common.**
+-dontwarn org.checkerframework.**
 -dontwarn org.xmlpull.**
 -dontwarn org.apache.log4j.**
 -dontwarn org.fourthline.cling.**
@@ -24,6 +26,7 @@
 -dontwarn java.util.**
 -dontwarn java.lang.**
 
+
 -keep class forge.** { *; }
 -keep class com.thoughtworks.xstream.** { *; }
 -keep class org.apache.commons.lang3.** { *; }