libcutils: add android_get_control_socket() test

android_get_control_socket() checks if the resulting file descriptor
is valid, open and matches the socket bound name reference, which on
purpose will fail if a symbolic link is in the path rather than using
a fully qualified path.  If there are any non-alpha and non-numeric
characters in the name, they are replaced with _.  Add unit test.

Test: gTest libcutils_test --gtest_filter=SocketTest.android_get_control_socket
Bug: 32450474
Change-Id: I27a6419012033ef8bd6ca04f3e479d01264d8c49