Fix several Lint warnings

app/src/main/java/com/limelight/AppView.java

@@ -590,7 +590,7 @@ public class AppView extends Activity implements AdapterFragmentCallbacks {
         listView.requestFocus();
     }
 
-    public class AppObject {
+    public static class AppObject {
         public final NvApp app;
         public boolean isRunning;
 

app/src/main/java/com/limelight/PcView.java

@@ -719,7 +719,7 @@ public class PcView extends Activity implements AdapterFragmentCallbacks {
         registerForContextMenu(listView);
     }
 
-    public class ComputerObject {
+    public static class ComputerObject {
         public ComputerDetails details;
 
         public ComputerObject(ComputerDetails details) {

app/src/main/java/com/limelight/binding/input/ControllerHandler.java

@@ -1616,7 +1616,7 @@ public class ControllerHandler implements InputManager.InputDeviceListener, UsbD
         usbDeviceContexts.put(controller.getControllerId(), context);
     }
 
-    class GenericControllerContext {
+    static class GenericControllerContext {
         public int id;
         public boolean external;
 

app/src/main/java/com/limelight/binding/input/virtual_controller/VirtualController.java

@@ -22,7 +22,7 @@ import java.util.Timer;
 import java.util.TimerTask;
 
 public class VirtualController {
-    public class ControllerInputContext {
+    public static class ControllerInputContext {
         public short inputMap = 0x0000;
         public byte leftTrigger = 0x00;
         public byte rightTrigger = 0x00;

app/src/main/java/com/limelight/grid/assets/CachedAppAssetLoader.java

@@ -362,7 +362,7 @@ public class CachedAppAssetLoader {
         return false;
     }
 
-    public class LoaderTuple {
+    public static class LoaderTuple {
         public final ComputerDetails computer;
         public final NvApp app;