Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_ANDROID

src/audio/SDL_audio.c

@@ -64,7 +64,7 @@ static const AudioBootStrap *const bootstrap[] = {
 #ifdef SDL_AUDIO_DRIVER_OPENSLES
     &openslES_bootstrap,
 #endif
-#if SDL_AUDIO_DRIVER_ANDROID
+#ifdef SDL_AUDIO_DRIVER_ANDROID
     &ANDROIDAUDIO_bootstrap,
 #endif
 #if SDL_AUDIO_DRIVER_PS2
@@ -631,7 +631,7 @@ int SDL_ClearQueuedAudio(SDL_AudioDeviceID devid)
     return 0;
 }
 
-#if SDL_AUDIO_DRIVER_ANDROID
+#ifdef SDL_AUDIO_DRIVER_ANDROID
 extern void Android_JNI_AudioSetThreadPriority(int, int);
 #endif
 
@@ -646,7 +646,7 @@ static int SDLCALL SDL_RunAudio(void *devicep)
 
     SDL_assert(!device->iscapture);
 
-#if SDL_AUDIO_DRIVER_ANDROID
+#if defined(SDL_AUDIO_DRIVER_ANDROID)
     {
         /* Set thread priority to THREAD_PRIORITY_AUDIO */
         Android_JNI_AudioSetThreadPriority(device->iscapture, device->id);
@@ -746,7 +746,7 @@ static int SDLCALL SDL_CaptureAudio(void *devicep)
 
     SDL_assert(device->iscapture);
 
-#if SDL_AUDIO_DRIVER_ANDROID
+#if defined(SDL_AUDIO_DRIVER_ANDROID)
     {
         /* Set thread priority to THREAD_PRIORITY_AUDIO */
         Android_JNI_AudioSetThreadPriority(device->iscapture, device->id);

src/audio/android/SDL_androidaudio.c

@@ -20,7 +20,7 @@
 */
 #include "SDL_internal.h"
 
-#if SDL_AUDIO_DRIVER_ANDROID
+#ifdef SDL_AUDIO_DRIVER_ANDROID
 
 /* Output audio to Android */
 

src/video/android/SDL_androidevents.c

@@ -31,7 +31,7 @@
 /* Can't include sysaudio "../../audio/android/SDL_androidaudio.h"
  * because of THIS redefinition */
 
-#if !defined(SDL_AUDIO_DISABLED) && SDL_AUDIO_DRIVER_ANDROID
+#if !defined(SDL_AUDIO_DISABLED) && defined(SDL_AUDIO_DRIVER_ANDROID)
 extern void ANDROIDAUDIO_ResumeDevices(void);
 extern void ANDROIDAUDIO_PauseDevices(void);
 #else