fix emulator not found function

Author: ranaaditya

mode/src/processing/mode/android/EmulatorController.java

@@ -75,7 +75,7 @@ synchronized public void launch(final AndroidSDK sdk, final boolean wear)
     String gpuFlag = "auto";
 
     final File emulator = sdk.getEmulatorTool();
-    if (emulator == null || emulator.exists()) {
+    if (emulator == null || !emulator.exists()) {
       System.err.println("EmulatorController: Emulator is not available.");
       return;      
     }