Fix incorrect site-packages path breaking app at runtime

The keyboard app crashes at launch right now because it has outdated assumptions about the site packages folder and it tries to list things from there. This changes the path accordingly, and avoids a crash in the future if the path shouldn't be present/moved again.

Author: JonasT

testapps/testapp_keyboard/main.py

@@ -2,21 +2,28 @@
 
 import os
 print('imported os')
+import sys
+print('imported sys')
 
 from kivy import platform
 
 if platform == 'android':
-    print('contents of ./lib/python2.7/site-packages/ etc.')
-    print(os.listdir('./lib'))
-    print(os.listdir('./lib/python2.7'))
-    print(os.listdir('./lib/python2.7/site-packages'))
+    site_dir_path = './_python_bundle/site-packages'
+    if not os.path.exists(site_dir_path):
+        print('warning: site-packages dir not found: ' + site_dir_path)
+    else:
+        print('contents of ' + site_dir_path)
+        print(os.listdir(site_dir_path))
 
     print('this dir is', os.path.abspath(os.curdir))
 
     print('contents of this dir', os.listdir('./'))
 
-    with open('./lib/python2.7/site-packages/kivy/app.pyo', 'rb') as fileh:
-        print('app.pyo size is', len(fileh.read()))
+    if (os.path.exists(site_dir_path) and
+            os.path.exists(site_dir_path + '/kivy/app.pyo')
+            ):
+        with open(site_dir_path + '/kivy/app.pyo', 'rb') as fileh:
+            print('app.pyo size is', len(fileh.read()))
 
 import sys
 print('pythonpath is', sys.path)