Resolves #378, adding support for detecting ARMv8 on Android.

jme3-android/src/main/java/com/jme3/system/android/JmeAndroidSystem.java

@@ -122,9 +122,13 @@ public class JmeAndroidSystem extends JmeSystemDelegate {
                 return Platform.Android_ARM6;
             } else if (arch.contains("v7")) {
                 return Platform.Android_ARM7;
+            } else if (arch.contains("v8")) {
+                return Platform.Android_ARM8;
             } else {
                 return Platform.Android_ARM5; // unknown ARM
             }
+        } else if (arch.contains("aarch")) {
+            return Platform.Android_ARM8;
         } else {
             return Platform.Android_Other;
         }

jme3-core/src/main/java/com/jme3/system/JmeSystemDelegate.java

@@ -153,6 +153,10 @@ public abstract class JmeSystemDelegate {
             return false;
         } else if (arch.equals("universal")) {
             return false;
+        } else if (arch.equals("aarch32")) {
+            return false;
+        } else if (arch.equals("aarch64")) {
+            return true;
         } else if (arch.equals("arm")) {
             return false;
         } else {

jme3-core/src/main/java/com/jme3/system/Platform.java

@@ -88,6 +88,11 @@ public enum Platform {
      */
     Android_ARM7,
 
+    /**
+     * Android ARM8
+     */
+    Android_ARM8,
+
     /**
      * Android x86
      */