Convert libbinderwrapper_test_support to be a static library

Some unittests require libbinderwrapper_test_support.so and fail
because it isn't on userdebug images.

Bug: 30631078, 35804180
Test: `make dist`

(cherry picked from commit 6515f36e43082ea105115de7e34d9cd09c77220a)

Change-Id: I4d8878de8963d0cbd29d6aca4b233ba674121688