android: Experimental support for Android into  Piglit python part

This patch modifies framework/exectest.py. If Piglit is run after
build/envsetup.sh is sourced from Android sdk and lunch is run Piglit
will attempt to send the tests to connected android device and
execute the tests on the device bringing the results back to host
machine.

The operation is achieved by using bash scripting, scripts will be
dropped from python into user's home folder for the duration
of executing the tests.

There will be left additional files on the android device at
/data/tests

Signed-off-by: Juha-Pekka Heikkila <juha-pekka.heikkila at linux.intel.com>