Use boolean expects in unit tests

Certain gcc versions will give (per my understanding false positive)
warning when 'EXPECT_EQ' macro is used so that other argument is
'true' or 'false'.

For example, Ubuntu 16.04 has by default such a gcc version.

See some related discussion below:
https://github.com/google/googletest/issues/322

We have defined all compiler warning to be treated as errors, thus
above issue will lead to compilation error.

Simple fix is to use 'EXPECT_TRUE' or 'EXPECT_FALSE' instead. Those are
more readable, and thus better choice anyway.

Signed-off-by: Rolf Badorek <rolf.badorek@nokia.com>
Change-Id: Ib0f3841c1b6fe2cf95eac3e4dc0cbcba9c3c8268