Merge VideoBootStrap::available into VideoBootStrap::create

The two are only ever called together, and combining them makes it possible
to eliminate redundant symbol loading and redundant attempts to connect
to a display server.

src/video/android/SDL_androidvideo.c

@@ -70,12 +70,6 @@ SDL_sem *Android_PauseSem          = NULL;
 SDL_sem *Android_ResumeSem         = NULL;
 SDL_mutex *Android_ActivityMutex   = NULL;
 
-static int
-Android_Available(void)
-{
-    return 1;
-}
-
 static void
 Android_SuspendScreenSaver(_THIS)
 {
@@ -173,7 +167,7 @@ Android_CreateDevice(int devindex)
 
 VideoBootStrap Android_bootstrap = {
     ANDROID_VID_DRIVER_NAME, "SDL Android video driver",
-    Android_Available, Android_CreateDevice
+    Android_CreateDevice
 };