Supports InputAvailable events with GameActivity

This makes a small change to the C glue code for GameActivity to send
looper wake ups when new input is received (only sending a single wake
up, until the application next handles input).

When a wake up is received and we recognise that new input is available
then an `InputAvailable` event is sent to the application - consistent
with how NativeActivity can deliver `InputAvailable` events.

This addresses a significant feature disparity between GameActivity and
NativeActivity that meant GameActivity was not practically usable for
GUI applications that wouldn't want to render continuously like a game.

Addresses #4

examples/agdk-mainloop/.idea/gradle.xml

@@ -13,7 +13,6 @@
             <option value="$PROJECT_DIR$/app" />
           </set>
         </option>
-        <option name="resolveModulePerSourceSet" value="false" />
       </GradleProjectSettings>
     </option>
   </component>

examples/agdk-mainloop/src/lib.rs

@@ -11,7 +11,7 @@ fn android_main(app: AndroidApp) {
 
     while !quit {
         app.poll_events(
-            Some(std::time::Duration::from_millis(500)), /* timeout */
+            Some(std::time::Duration::from_secs(1)), /* timeout */
             |event| {
                 match event {
                     PollEvent::Wake => {
@@ -49,6 +49,9 @@ fn android_main(app: AndroidApp) {
                             MainEvent::RedrawNeeded { .. } => {
                                 redraw_pending = true;
                             }
+                            MainEvent::InputAvailable { .. } => {
+                                redraw_pending = true;
+                            }
                             MainEvent::LowMemory => {}
 
                             MainEvent::Destroy => quit = true,