build: Update generate scripts to use python3

Upcoming header scripts require python3 -- updated
Windows and Linux android-generate scripts.

Change-Id: Iba3b44d0999b5c28b9fc83800a4d54d46cbc2a4c
diff --git a/build-android/android-generate.sh b/build-android/android-generate.sh
index 04c837d..4c3da0d 100755
--- a/build-android/android-generate.sh
+++ b/build-android/android-generate.sh
@@ -21,13 +21,13 @@
 rm -rf generated
 mkdir -p generated/include generated/common
 
-python ../scripts/vk_helper.py --gen_enum_string_helper ../include/vulkan/vulkan.h --abs_out_dir generated/include
-python ../scripts/vk_helper.py --gen_struct_wrappers ../include/vulkan/vulkan.h --abs_out_dir generated/include
+python3 ../scripts/vk_helper.py --gen_enum_string_helper ../include/vulkan/vulkan.h --abs_out_dir generated/include
+python3 ../scripts/vk_helper.py --gen_struct_wrappers ../include/vulkan/vulkan.h --abs_out_dir generated/include
 
-( cd generated/include; python ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml vk_dispatch_table_helper.h )
-( cd generated/include; python ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml thread_check.h )
-( cd generated/include; python ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml parameter_validation.h )
-( cd generated/include; python ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml unique_objects_wrappers.h )
+( cd generated/include; python3 ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml vk_dispatch_table_helper.h )
+( cd generated/include; python3 ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml thread_check.h )
+( cd generated/include; python3 ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml parameter_validation.h )
+( cd generated/include; python3 ../../../scripts/lvl_genvk.py -registry ../../../scripts/vk.xml unique_objects_wrappers.h )
 
 cp -f ../layers/vk_layer_config.cpp   generated/common/
 cp -f ../layers/vk_layer_extension_utils.cpp  generated/common/