Changing Android save paths to now default to the 'external' dir from the device itself.

Merging the src/tuxpaint.c change from
https://github.com/tux4kids/Tuxpaint-Android/pull/18
(e23803b1f2)

Per Terrence

docs/CHANGES.txt

@@ -7,7 +7,7 @@ Various contributors (see below, and AUTHORS.txt)
 http://www.tuxpaint.org/
 
 
-2022.July.3 (0.9.29)
+2022.July.7 (0.9.29)
   * Bug Fixes:
     ----------
     * Opening and immediately dismissing Color Mixer could cause
@@ -92,6 +92,8 @@ http://www.tuxpaint.org/
 
     * Various Android port updates
       * FIXME: Pere & Terrence, can you enumerate them here???
+      * Changing Android save paths to now default to the 'external' dir from the device itself.
+        https://github.com/tux4kids/Tuxpaint-Android/pull/18
       Terrence Sheflin <terrence.sheflin@gmail.com>
       Pere Pujal i Carabantes <perepujal@gmail.com>
 

src/tuxpaint.c

@@ -22,7 +22,7 @@
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   (See COPYING.txt)
 
-  June 14, 2002 - July 3, 2022
+  June 14, 2002 - July 7, 2022
 */
 
 #include "platform.h"
@@ -26406,6 +26406,12 @@ static void setup_config(char *argv[])
       picturesdir = GetUserImageDir();
 #elif __APPLE__
       picturesdir = strdup(apple_picturesPath());
+#elif __ANDROID__
+      picturesdir = strdup(SDL_AndroidGetExternalStoragePath());
+      char* substring = strstr(picturesdir, "/Android");
+      if (substring != NULL) {
+        strcpy(substring, "/Pictures");
+      }
 #else
       picturesdir = get_xdg_user_dir("PICTURES", "Pictures");
 #endif