Implement an optional guard band for screen-space effects

When the guard band is enabled, the effective rendering area is
increased by a certain amount (currently 16 pixels on each side) so
that screen-space effects (e.g. SSAO, SSR, DoF) behave better around
the edges of the screen. Of course, this comes at a performance and
memory cost.

Currently the guard band is not configurable other than being optional.

Added c++, java and js bindings.

android/filament-android/src/main/cpp/View.cpp

@@ -461,3 +461,11 @@ Java_com_google_android_filament_View_nPick(JNIEnv* env, jclass,
         JniCallback::postToJavaAndDestroy(callback);
     }, callback->getHandler());
 }
+
+extern "C"
+JNIEXPORT void JNICALL
+Java_com_google_android_filament_View_nSetGuardBandOptions(JNIEnv *, jclass,
+        jlong nativeView, jboolean enabled) {
+    View* view = (View*) nativeView;
+    view->setGuardBandOptions({ .enabled = (bool)enabled });
+}