ALLJOYN-1973: Remove Android NDK conditionals from SConscript files.

Change-Id: I2c641371d7a01edbd2ea2bd679053bd5caec8f19
ALLJOYN-1973 Must define GTEST_OS_LINUX_ANDROID for unit tests

GTEST_OS_LINUX_ANDROID must be defined for the when building the google
test or we get a compilation error reported from the function wcscasecmp
is encountered.

Change-Id: Ia80fe7095cfafa220049975ead70fdf016cdf1f1